Similar case here. After installing avast and upgrade to pro I have no internet access and no pop3 and smtp. I figured that disabling www shield and mail shield helps, but it is dangerous (I've bought avast to protect, not to disabling protection). PC was brand fresh new WITHOUT any preinstalled anti-virus. I have Win 7 Professional x64 installed (by myself), few user profiles with administration privileges.
I will try to uninstall it using avast removal tool and reinstall it again, but still I'm surprised - I've never had such "features" before, but before I had avast 4 pro and upgrades and different OS (XP) so this is different story.
I'll tell you, if "uninstall and install again" workflow help me in my next post.