Avast 8 & Blizzard Installer / Launcher

After reinstalling windows 8, and avast internet security v8. I went to install world of war craft cataclysm. The launcher was unable to connect to server. I had already installed star craft 2, but it now blocks the sc2 installer from allowing me to play the game. the screen pops up but unable to click the play button. I un-installed avast and rebooted pc. i was able to install world of warcraft and play sc2. So I know that avast was causing the problem. How do I fix this?

Thanks!

ok, I think I might know part of the problem. I have notice a lot of browsers and security software has blocked adobe flash due to the recent security flaws. I believe this is what has happened in the up date from v7 to v8. Should I be able to just add the launchers exe as safe in the firewall settings? Or is there a way to allow all adobe flash to firewall or safe zone?

I have Firefox 19.0.2, Opera 12.14, MSIE 8 on the WinXP and MSIE 9 on Win7. They all allow the latest Flash version, currently 11.6.602.167. Older insecure versions of Flash are blocked.