I've gotten that error on a lot of *cough*illegal*cough* versions of Windows XP. Got it mostly playing games (the more RAM intensive ones, at that) and coming back from sleep/hibernation. If re-installing drivers didn't work, I'm not sure what else to do. From what I read, its not always related to networking, but drivers and RAM. If it doesn't happen often I guess I wouldn't worry to much about it, I've only gotten it to go away by 1) Reinstalling Drivers and 2) Doing a clean install.
But if you ever catch the code that could prove helpful. What I would do is update all of my drivers, and not that just of the NIC.