Access internet throught ICS on XP

Ihave ics running on a XPpro desktop. My win2k client desktop can access the internet perfectly. I installed xp pro on the same desktop as win2k ( dual boot). installed with no errors and can access the windows update site and register xp with microsoft.However,I can only browse and access Microsoft sites!- hotmail,msn,windows update,etc. no other sites. If I disconnect the machine from the ICS computer and attach directly to my cable modem, I can surf everywhere. If I connect everything back up and boot to the win2k desktop, I can surf everywhere. Only on the xp desktop will it surf only the Microsoft sites and nowhere else. I have checked every possible config setting I can find in the resource kit, registry,hacker books, but this has mestumped. Has anyone else see this?