URL Blocked query

Hello everyone,

I am getting the URL Blocked notification since I updated avast to a newer version. The notification seems to get triggered even on legit sites like youtube. Seems like the anti-virus is blocking a redirect to the following address:
superfish.com/ws/sf_main.jsp?dlsource=DiigoreadlateruserId=xxxxxxxxxxxx

I am using Google Chrome and my OS is Windows XP Pro SP3.
Is the brower infected? These notifications do not appear when I access youtube on Firefox.

Please suggest me appropriate measures. Also, if I have missed out any necessary information, let me know.

Hi,

Some information:
http://www.mywot.com/en/forum/8054-how-come-google-com-use-superfish-com-java-script
http://www.mywot.com/en/scorecard/superfish.com
"Used for advertising. Useful for Google and others to gather information about you. Assists spam advertisers. If you already use Google Chrome, it won’t make any difference one way or the other. Otherwise it’s best to give it a miss. " ~fenian 03/07/2012