Your rig is certainly powerful enough to run this game and still have enough power leftover to crunch seti workunits

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I noticed you're using the onboard sound for your nforce2-based MB. This uses the Realtek ALC650E chipset to handle the sound processing. In the past, some users have found that turning down the sound acceleration via dxdiag has helped to reduce the occurrences of crashes.
Another thing to check is a trace or pingplot to the hitech servers. If you're losing packets along the way, you might be getting thrown out because of that.
Hope some of this helps.