I found other posts regarding this problem. The fix utilities from 3rd parties did not work for me.
Now the data for my circumstance.
As you may guess, Avast Free version 5.0.677 blocks browser traffic (except for Chrome) when the Avast Web Shield is used. The only alternative is to disable the web shield (which I don't really want to do, but...)
Products which may be contributing to the problem:
1.) Windows 7 (fully updated as of 11/24/2010)
2.) Avast Free (fully updated)
3.) Comodo Firewall with Defense PLus
4.) Norton Online Family (monitoring and blocking material not appropriate for my kids)
Thanks for any help you may offer.
I Love Avast! Thank you!
TW