There have been other users who have reported problems with PCT FW.
I have used PCT FW in the past with Avast, but with the 6.0x version as a test and never experienced a problem with being unable to access web sites. I found that PCT FW was very "hackable" however and not as secure as other FW's in testing and someone tried to get into my machine while using this FW but I had another security software to prevent the intrusion.
I would suggest that if you really insist on using PCT FW, that you go under Advanced Settings to make sure that nothing from Avast is being blocked (you will see a red dot next to it if it is blocked). If it is blocked, right click and change the setting.
Your other option is to use a different and stronger FW. Suggestions that are compatible with Avast are: Windows FW, Avast IS (AIS), Online Armor, Outpost, Comodo (with out AV). The last 3 have free or paid versions...you get what you pay for...more protection and the ability to configure the software.
As with any security software, you should add your FW (other than Windows FW) to the Avast exclusions.
Since your OS is Windows 7, I would recommend that you start with using Windows 7 FW with Avast to see if your problem is resolved. You want to make changes one at a time to see what is causing your problems. Report back to us to see if this fixes your problem. Thank you.