hello, can you try to replicate this behaviour when you launch firefox in safe mode once? if not, maybe an addon is interfering here... (plugins are left enabled in safemode though)

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Also, scan with some other malware scanners Troubleshoot Firefox issues caused by malware

I'm having this problem as well since yesterday, and I haven't installed any add-on. The only thing I changed from it is that I updated Java, so I suspect it may have to do with the Java connectors. I've disabled the Java Platform SE 7 U5 10.5.1.255, will see if it happens again.

Just replying to my answer to state that the issue keeps happening with the specified Java connectors disabled.

I'm reposting here as well because it seems someone has found the issue. Link in Spanish:

http://mx.answers.yahoo.com/question/index?qid=20130119101338AAlEUkh

Go to the program files folder, and there should be a folder named "SaveByClick". The folder contains two files: a .dll and a uninstaller. The .dll activates repeatedly the unistaller file and Avast blocks it. So simply delete the entire folder and the problem will disappear.

I'll try that as well and in a few days I'll report if it solves the issue for me.

thx i dont have SaveByClick , i search the also =

what i did , full scan using AdwCleaner then SUPERAntiSpyware .. delete everything AdwCleaner found and restart , rest my profile and 3 day til now didn't get the message hope this help

thx all for help