Ok. after lurking around other threads I think I found the possible solution.
Disabling self defense module might be the answear.

http://forum.avast.com/index.php?topic=119008.30
http://forum.avast.com/index.php?topic=121404.0
http://forum.avast.com/index.php?topic=121440.0
http://forum.avast.com/index.php?topic=121436.0

I guess I should search first next time before asking.