Problem with internet browser(IE and Firefox)?

On my computer (Windows XP) after browsing for several hours, both browsers (IE 7 and Firefox 2.0.0.2, regular and safe mode) quit displaying any website. Nothing displays on Firefox, and IE says there is no connection. I can ping ip addresses and the localhost, and if I'm downloading any files or using bittorrent, they continue to work. I've tried the usual, clearing the cache, release/renew ip address, diagnose the connection with built in programs in windows XP. If it helps, I use CA's firewall and avast antivirus. The problem stops if I restart or log off and log on again. Any suggestions to point in the right direction would help, even if it isn't a full solution. I am usually good with computers, so don't be afraid to be technical.

Problem with internet browser(IE and Firefox)?photoshop

have you tried with the firewall and av off- use the xp firewall

also can you ping outside of your network???

can you telnet to google etc???

might be malware try running a rootkit revealer

strongly recommend system file check (start- run- sfc/scannow - return), might be a tcp stack prob try http://support.microsoft.com/kb/299357

tayo safe mode firefox not xp

Problem with internet browser(IE and Firefox)?symatec

its cuz ur in safe mode

if u restart, and go back to safe mode, the same thing'll happen after a while

it does that for some reason.