http://forum.avast.com/index.php?topic=84220.0

The latest beta build of avast 6.0.1279 and the webrep does work with FF 6.0.1 and later FF beta builds. So in due course when the next program update is released it will work.

not only avast most of the antivirus program release their browser compatibility after releasing browser,even download manager like IDM,DAP also do same things

^ that is not 100% correct. Some security program vendors are prepared when Mozilla releases a new version of Firefox. Norton for one, had a patch ready and released their update on the same day that both Firefox 5.0 and 6.0 were released. And it's not like the release of a new version should be a surprise, there is a 6 week beta test period before the actual release is made, where nothing is changed that should affect a security program. If they need more than 6 weeks to test and fix their stuff for the new version, they need a new ringmaster for their circus act.

The previous 3 updates for FF the problem was resolved after about 3 weeks. This time, that isn't the case. I don't want to change browsers but if I have to I'll have to I guess. Anyway. Thanks to everyone who responded ; )

With all the free (for personal use) anti-virus applications out there, why not switch to a different application which doesn't have that problem. Avira Personal Free - http://www.free-av.com/ - doesn't install a silly add-on that has compatibility issues with Firefox after a Firefox update. In most cases those silly little add-ons only duplicate features that are a ready built into Firefox, and add little more than "bells & whistles" or "eye-candy".

http://www.mozilla.com/en-US/firefox/phishing-protection/
Firefox 3 or later contains built-in Phishing and Malware Protection to help keep you safe online. These features will warn you when a page you visit has been reported as a Web Forgery of a legitimate site (sometimes called “phishing” pages) or as an Attack Site designed to harm your computer (otherwise known as malware).

• avast already release FF 6 patch
• run program update from Avast UI or install your Avast from Scratch
• Choose your Product Below
• Free AV: http://files.avast.com/iavs5x/setup_av_free.exe
• Pro AV: http://files.avast.com/iavs5x/setup_av_pro.exe
• IS: http://files.avast.com/iavs5x/setup_ais.exe

• check your Avast plugin and addon compatible or not