Dawn of War 2 - LAN stuttering

Alright long story short I got my dad DoW2 so we could play on LAN

It was just me and him on a 1v1 going up against eachother and he would lock up and stuttering at least every 15-20 seconds regardless of how much was going on at the time (So its not tied into FPS)

I had him launch a single player skirmish with 7 bots and they kept mass producing units and he didn't stutter once SO I'm assuming this is some kind of bizarre network problem.

I don't seem to have the problem in this LAN situation, and I can play just fine online with others so I've narrowed it down to his rig.

Rig Specs on his are here:
Intel Core2Duo E6400 @ 2.13Ghz
Kingston HyperX DDR2-800 @ 5-5-5-18 2.0v
eVGA GeForce 8800GTX
500w Antec PSU
MSI 650i MoBo

Does anyone know of some kind of patch/tweak/glitch I'm missing here? We double checked all his NIC settings and our router seems to be in good working order...not to mention this only happens in DoW2 (We played a couple other RTSs over LAN like Supreme Commander and Dawn of War 1 with no problem)

Ideas?

*edit*
He also is running it through STEAM so its totally updated, along with all his drivers.

Meh scratch this thread.

I ran Supreme Commander with a bunch of AIx's coming at me to flood the game with units/ownage and it was stuttering horribly. During the thick of this Speedfan was reporting CoreTemps on Core0 and Core1 on the CPU exceeding 100c.

Turns out the stock Skt775 Heatsink came loose and wasn't making contact...damn near fried the CPU. Redid the Heatsink and AS5 and seems to be doing fine now *slaps forehead*