Hey beta, you heating your domicile with the exhaust heat from your vid card? 1024x768@85Hz? Seriously? Pull your refresh rate down, like a lot, it's no wonder your machine says enuf every so often. For the record, you've got a gig more ram, and a better vid card (I'm running a Sapphire HD4350), and I can run at 1920x1080@59Hz (1680x1050 in-game) for weeks without dc'ing except for when I get whacked by the backup DC. It's not pets that are your problem.
Service packs may be an issue as well, shame you're out of the support window for XP Home.
Just an observation by a know-nothing botter... Or am I a cheat this week? I lose track, it changes up so much.