Vista SP2 causing blue screens on ad-hoc?

Greetings!

Several friends and I have been running a gaming network in Afghanistan to pass the evenings. We play CoD4, CoD5, and BF2 nearly every night. Due to a someone stealing our wireless router, we've been running an Ad-Hoc network using Vista SP1 until our new router arrives. All computers on the network are either Vista SP1 or XP. Last night a new guy came to play and as soon as he connected to the Ad-Hoc, anyone without an HP laptop started having blue screens (all using Vista SP1). Here is a list of our "regular" players systems:

Dell XPS 15, Core2Duo 2.5(ish), 4GB RAM, 512mb gfx, Vista SP1
Dell XPS 16, Core2Duo 2.8, 4GB RAM, 1GB gfx (mine), Vista SP1
2x HP 8000 series, unk CPU, 1-1.5GB RAM, 256mb gfx, XP Pro SP2 & 3
Toshiba Satellite, unk CPU (2+ghz), 2+GB RAM, 512mb gfx, Vista SP1
HP (6 months old, high-ish end), unk CPU, 2+GB RAM, 512 gfx, Vista SP1

The new guy has an identical laptop to the last listed HP laptop but he is running Vista SP2. None of us have had any issues until the Vista SP2 laptop entered the network. None of the HP laptops had any errors, only the Dell and Toshiba laptops experienced blue screens (repeatedly). Once the Vista SP2 laptop was removed from the network, there were no issues for the rest of the evening.

Is there a known issue with HP laptops running Vista SP2 causing problems with non-HP laptops not running Vista SP2? We'd hate to single the guy out and ban him from gaming, but right now this is our only option. We, as a group, do not want to upgrade to Vista SP2.

Your assistance is greatly appreciated.