Since most users seem quite happy with 6, in spite of a few initial problems, tell us a bit more about your system. (I am currently running 6 on 4 computers, 1 AIS and 3 free, W7x64 and Vistax32 with no issues.) Coexisting with Windows firewall and Online Armor++, plus Prevx.
What is your OS? What is your firewall? What other security software are you using now and were you previously using? A lot of this sounds like residual interference from something like Norton. If you previously had other security software, did you remove it with something from http://uninstallers.blogspot.com/ .
Did you uninstall from safe mode using the Avast! uninstall tool http://files.avast.com/files/eng/aswclear6.exe ?