Infection Blocked - Again and again-

From today is my Free Avast again, again and again saying :

Infection Blocked

URL : A script started by C:/ Programmer/Mozilla Firefox / Fi …

Infection HTML : Script-inf

Relax, your avast just saved you from a virus
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It happen EVERY time i open with firefox

Please help me get rid of that

Greetings Jørn Rudolph from Copenhagen, Denmark

From today is my Free Avast again, again and again saying :
this indicate possible infection....

for help, follow logs guide at top in viruses and worms forum section. http://forum.avast.com/index.php?topic=53253.0