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Normally I wait for sometime before upgrading WordPress installations. But this time I jumped to WordPress 2.5 when I came across serious security issues in 2.2.x series. Some of my blogs which ran under 2.2.x versions were badly hacked and I had to spend a lot of time recovering them! The hacker modified most of my posts and cleverly inserted hidden links. Also he installed a backdoor php file in the current template folder! This ensured that even after upgrade he can control my WordPress blog.

I detected the problem only when I realized that my blog is no longer in the Google search index!

The WordPress hacking became so widespread that Technorati has special process in place to quarantine infected/hacked WordPress blogs! There are reports of WordPress 2.5 vulnerability, but it is better to upgrade to 2.5 than stick with 2.3.3. The important thing is to upgrade as soon as a release is out rather than cling to a version for which hacking scripts may be sold in warez forums! So I am keeping my thumb on the WordPress upgrade button waiting for 2.5.1 

After the upgrade I came across an interesting  issue when I tried to post through Windows Live Writer. It responded with an error message – Invalid response document returned from XmlRpc server. I initially thought that it is a bug with Windows Live writer and compatibility issue with WordPress 2.5. Then I tried posting the same from the WordPress admin. When I tried to upload an image I got the following error,

– Fatal error: Call to undefined function wp_constrain_dimensions.

Then I realized there is some problem with the WordPress 2.5 upgrade. Here is how I resolved the problem. First I deleted all the php files in the WordPress root folder (except wp-config.php) and then deleted wp-admin and wp-includes folder. After ensuring that all old files are deleted, I uploaded WordPress 2.5 files again. That resolved the issue with Windows Live Writer!

April 22, 2008 | Posted in Security, Tech Tips, WordPress | No Comments »

In Windows Vista, the default location of “my documents” folder is “c:\users\username\documents”. In this path “username” stands for the Windows Vista user account on which you are logged on.

“My documents” folder is the default directory where applications are supposed store output files. For example if you are using Visual studio, the default location for new projects are under “\visual studio 2008\projects”. This means that most of the user data that you want to backup will end up in “my documents” folder.

It is possible to point “my documents” to an alternate folder. I normally point to a different drive and then backup the drive on a weekly basis. Changing “my documents” folder location is easy,

1. Right click on “c:\users\username\documents” folder.

2. Select properties and then from the properties window select the location tab.

3. Change the location to an alternate location. Click on apply. Windows will ask whether you want to move all the files to new folder. Select “Yes”.

Now your “my documents” folder is changed to the new location.

March 23, 2008 | Posted in Tech Tips | No Comments »

When you transfer your domain from one host to another, you change your nameserver configuration. But the problem is that sometimes it takes a while for the nameserver change to propagate through the DNS server of your ISP. Sometime the DNS configuration is cached on your computer or browser session. Here are some tips to remove DNS cache and also to see hosting server changes immediately.

Clearing DNS Cache on Microsoft Windows

From the command prompt (start=>run=>cmd) enter the command ipconfig/flushdns. This will purge the DNS resolver cache.

This will remove dns cache entries from your machine. But you will still have a problem if your ISP DNS cache is holding the old DNS entry. There is a simple trick to bypass DNS mechanism in Windows.

Search for the file named “hosts” inside Windows folder. In my Windows Vista machine this is located inside c:\windows\system32\drivers. Add a new line like the one below(replace domain with your domain and IP address with the IP address of the Web host machine where your domain is relocated).


“hosts” is first searched by Windows to resolve a domain to an IP address effectively short circuiting the ISP DNS.

Clearing DNS cache on Linux

On linux you can use the command sudo /etc/init.d/nscd restart  to clear DNS cache. This assumes that nscd is already installed in your linux box.  On ubuntu you can try restarting the networking service using the command sudo /etc/init.d/networking restart.

The above mentioned Windows trick can also be applied on linux machines. In linux you need to modify /etc/hosts file and add your domain and domain hosted server ip as given below. You need restart the networking using sudo /etc/init.d/networking restart for this to work.


Clearing DNS cache on Mac

On a Mac OS X you can clear DNS cache by typing the command lookupd -flushcache.

Clearing DNS cache from browsers

DNS is also cached at browsers. Most of the time this is cleared when you close all the browser sessions. In Firefox this can be forced by clearing the private data from tools menu.

March 22, 2008 | Posted in Tech Tips | No Comments »

If you are using your own WiFi router and if you forget the WEP or WPA key, the easiest option is to create a new key! After all you have complete access to your router!

But what if you are connecting to an external WiFi router? The problem is once you enter the key, Windows remembers the key for the network and it won’t ask again. After a couple of days you have forgotten the key. You still have access to wireless network, but you want to find the key Windows is using so that you can back it up! Another scenario is when you want to configure the same wireless network on a different machine.

Fortunately there is a freeware tool(WirelessKeyView) which can display WEP/WPA wireless keys stored by Windows. You can download WirelessKeyView from here.  You can see this software in action below.

This utility can recover network key only if it is stored by ‘Wireless Zero Configuration’ service of Windows XP and by the ‘WLAN AutoConfig’ service of Windows Vista. Also note that you need to have administrator access to machine for this to work!

Programs such as this work using Windows API which expose WEP/WPA keys!

| Posted in Software Reviews, Tech Tips | No Comments »

Finally the much awaited Windows Vista service pack 1 is available for download! The complete service pack download is over 420MB(!) so don’t even think of downloading it over dialup. This service pack mainly consists of quality improvements, support for emerging hardware and standards and infrastructure optimization.

When Windows vista was released there were many who thought it would be a failure. Who would want to upgrade from the stable Windows XP? But Windows vista went on to sell over 100 million copies and has in turn become the fastest selling operating system in history! One of the areas where Windows Vista is much better than XP is the system security. Microsoft had invested a lot of effort in improving security architecture of Windows and it is beginning to payoff.

What is inside Windows Vista SP1?

1. Quality improvements
Windows Vista initially supported around 13,000 hardware components. With SP1 this number is increased to 54,000 components. Application and device compatibility improvements are many in Windows SP1.

Reliability improvements in SP1 include networking reliability improvements (for WiFi and IP6) and improvements to NTFS and EFS.

Performance enhancements include major speed/bandwidth improvements while accessing network shares, faster file copy (upto 45% faster!), improved battery life for laptops and faster access to compressed folders.

There are also a number of security improvements including support for new security standards.

2. Support for emerging hardware and standards
This include enhanced support for 64bit computers, support for new filesystem called exFAT and has support for Direct3D 10.1. The new standards supported include the wireless standard 802.11n, SHA 256 and SSTP (secure sockets tunnel protocol).

3. Infrastructure optimization
Windows vista SP1 introduces a concept called hotpatching. This allows updates to core components even when they are in use! This will definitely reduce the number of restarts required during an upgrade. Windows auto update is made smarter to deal with transient errors such as sharing violations and power failures. There are also a couple of improvements to Windows management such as enhanced network diagnostic tool and ability to configure disk defragmenter on a volume basis.

There are a number of programs that may not work once Windows Vista SP1 is installed. These include BitDefender AV,Fujitsu Shock Sensor,Jiangmin KV Antivirus 10, Jiangmin KV Antivirus 2008, Trend Micro Internet Security, Zone Alarm Security Suite, Iron Speed Designer, Xheo Licensing. Free Allegiance, NYT Reader, Rising Personal Firewall and Novell ZCM Agent. Windows Vista SP1 also won’t work with certain hardware which include audio/display drivers from Realtek and Intel.

It is better to use Windows update instead of downloading the SP1 directly. Windows Update can detect driver problems before installation. My advise is to wait for a couple of days before applying SP1 patch. There could be serious compatibility issues with certain hardware and software.

March 20, 2008 | Posted in Software Reviews, Tech News, Tech Tips | No Comments »

Orkut has recently enhanced the find friends functionality on the profile page. Now you can add friends using email contacts in your external email accounts. Currently Hotmail and AOL email accounts can be used (Official Orkut blog mentions Yahoo as well, but I am unable to see Yahoo in the list). According to the official blog, more external email providers will be added to this list soon!

For adding contacts from external email accounts, you need to give your account id and password. If your contacts are using gmail and they are on orkut, you can directly add them after importing them. For contacts who are not on Orkut, you can send an invitation asking them to join Orkut.

| Posted in Tech Tips | No Comments »

Youtube is currently the most favorite video sharing site out there. But the default video quality in Youtube is not very good. This is to ensure smooth video playback for majority of internet users who has bandwidth of 512kbps or less.

Whenever a video is uploaded to Youtube (.wmv, .avi, .mov, .mpg), it is automatically converted to a flash file format with a resolution of 320×240 pixels. The default data rate is about 240kbps.

But in many countries (korea, US, UK) broadband users have high bandwidth up to 8mbps! YouTube is currently encoding the videos to higher resolution and higher quality for users from these countries. But you need to explicitly enable it! Here is how,

Consider the following YouTube URL – http://www.youtube.com/watch?v=QAE2-FQHkok . When you watch this video, there is a link on the bottom which says watch this video in higher quality.  Another way to turn on high quality is by appending &fmt=6 to the URL. Hence http://www.youtube.com/watch?v=QAE2-FQHkok&fmt=6 will enable high quality video at 448×336 resolution and the audio quality is also improved. If you attach &fmt=18, the video resolution increases to 480×360 and the video is downloaded as an MP4 file!

If you are always logged into your YouTube account, you can enable high quality videos forever by selecting Account->Video Playback Quality->I have a fast connection. Always play higher-quality video when it’s available.

High resolution support is still in experimental stage and only a very small set of YouTube videos support this. Obviously for this to work, the uploaded file should be of higher quality!

March 19, 2008 | Posted in Tech Tips | No Comments »

Organizations, schools and even Internet cafes are using Internet filters such as Net Nanny and CyberPatrol to block access to specific Web sites.  In fact when it comes to children accessing the Web, these softwares are required to shield them from po*n sites. Unfortunately the same tools are used against freedom of speech as well.

Schools and organizations mainly use these tools to block po*nography sites and social bookmarking sites such as orkut, facebook and myspace. One of the easiest mechanisms used to bypass these controls is the Web proxy.  There is a cat and mouse chase between system administrators and proxy operators. The more sites/ip addresses are banned, more new ones appear everyday!

Some of the content filter software are intelligent enough to look for keywords in the content access and block it. But this method is unreliable and can cause problems with allowed Internet access.

But using web proxies to access banned Web sites is not a good idea! Here is why,

It is against company/school rules! – The Internet filters are installed for a purpose. Trying to bypass them will violate the rules of the school or the organization from which you are using the proxy site. This can lead to loss of your job or you may get suspended from the school. Remember, it is easy for an administrator to find out that you are using a Web proxy.

Identity theft – The proxy servers you access may be run by anonymous people. They don’t run it for charity. Most of them run the proxy servers to earn advertising money and some of them even use it for identity theft! When you access orkut via a proxy server, your login/password is going through the proxy server. The proxy administrator can easily capture your login information to steal your identity. So never use a proxy server to access your bank accounts or credit card accounts!

Now if you are one of those proxy administrators, beware of the risks involved in running a proxy server. People may use your proxy server for various spam activities such as email spam. Similarly they may use your proxy server to initiate hacking attempts at important Web sites. In many countries (India for example) for any illegal activity via the proxy server, the proxy administrator is legally liable!

March 10, 2008 | Posted in Internet, Tech Tips | 1 Comment »

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