There seems to be a recurring theme to this problem; I was also having the same type of problem-slow or nonloading webpages with Avast update and ZAP.
Shutting down the firewall cured it, but of course we ALL know that is like playing cowboys and indians with a tactical nuke. So here is what I did to fix (so it seems) the problem...
- download the FREE version of Zone Alarm
- unload ZAP running on the computer and uninstall
- re-install Zone Alarm (firewall only) and do not activate the "free trial" for the Pro version (I believe this is where the trouble lies)
- reboot and let 'er rip!
Realizing of course that everyone's machine is different, so this may not be a cure-all; but my guess is that it will remedy a large portion of problems that are similar.
Running : Win2k (sp4), 1g ram, 950 Athlon, avast, spywareblaster, spybot S&D, ccleaner, ad-aware, and Zone Alarm ...FREE!
Hope this helps
-Mike-