The mouse, GUI, and performance problems will occur when the system is under large amounts of stress of any kind.

I agree with this totally agrafuese. Thing is now for me these faults always happen after 3 hours use, I left my system on but no internet connected and it didn't happen.
To me it sounds like some kind of memory leak, whatever it is it obviously mounts up over time and then causes the instability.
I would love for someone else to try using there system for over 3 hours with no internet just to see if they get the same results!