Well avast 4.8 doesn't block (it isn't a firewall) but scans and alerts to infection and I presume that hasn't happened ?
What errors are being displayed when you try to connect ?
Your firewall shouldn't be a problem either as XP's firewall has zero outbound protection (a hole in your system security).
Exactly where you trying to connect (full URL) ?
Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?
What other security based software do you have installed ?
When I open EPX 5.5 it will not get software updates "Invalid response from server, software update check failed." and will not connect to server.
and "Error: No records were retrieved. You Must re-enter your User ID and Password. Please make sure you do not have your CAPS-LOCK key on.
Unable to retrieve your account profile from Eventpix.
Error: Invalid response from server."
My user name and password are correct as I can access the URL with my browser. Just cannot upload to their server.
http://www.eventpix.com using their program EPX5.5
I had AVG previously and uninstalled it. Also Zone Alarm which I turned off.