AVAST keeps warning me when I using every search web site

Hi all:

I am facing a situation that is when I use FireFox (ver 14.0.1) to search information through google, yahoo, or bing. AVAST Internet Security (ver 7.0.1466, virus definition version: 120821-0) keeps pop-up warning message to show me that AVAST has blocked a “Malicious URL Blocked”. The strange thing is when I use IE to do the same thing, AVAST didn’t show warning message. Also, I scanned my laptop through “Boot-time scan”, no virus found.

For warning screen shot, please see attachments.

Is this a fake warning? Please help, thanks a lot.

Hi all,

This problem has been fixed.
For how to fix this problem, please check below thread.
http://forum.avast.com/index.php?topic=102762.0

I,m glad you solve a problem