Hmmm wondering if your game file is corrupt or something. For it to only do it on that specific bonus in that game even after trying different OS, it's prob not the OS.
I will note when I first got my g23 machine before I did all the ram + SSD upgrades, we loaded the game on GK interface, 2gb ram, regular HDD, 625 AVP and NO dedicated graphics card - and while that was the one game that really stuttered when playing, it still ran and the bonus didn't freeze the machine, so I don't think it would be hardware related.