Barring the obvious like a rough internet connection, viruses, heat issues, physical connections, powersupply and hardware conflicts, I'm thinking that this system is on the low end hardware wise for the game to run well.
I would turn every game setting possible down to its absolute minimum.
Try using the texture cache feature if you can.
Also need to check for updated drivers for graphics and sound and check to see if major hardware components are sharing IRQ's.
Do you disco at random or does it happen at about the same time ingame? Is there anything you are doing at the time of disco (firing, using the mic, flying in high congestion area, etc?) that is consistent?
All I can think of right now.
