After switch user web pages do not display

Instead of logging out, when I leave my computer I just do a switch user. Even though I have only one profile in XP, It keeps ppl off my comp. When I go back into my account the next day or several hours later, my web pages will not pulll up. "findting www.blah.com" MSN messenger works fine, and even the connection seems to be getting information. I just cannot pull up pages, outlook doesnt connect and niether does IRC. I have to reboot and everything is fine. What might be the solution to this problem? my computer. 1.73 xp 2200 [email protected] 40gig. ati9000

thanks,

 

Are you using a firewall? Some firewalls have a setting like if the screen saver comes on, lock the internet.