I also been having the same problems with my Lock On FC.
Random crashes.
I did a complete reinstall using the "vanilla" instructions, but still have crashes. I've tryed adjusting my graphics from lowest to highest with the same results.
My specs are...
Vista Ultimate x64
Intel i17 920 2.67Mhz (@stock speed)
9 Gb DDR3 Corsair 1333 (@stock speeds)
Nividia 9500GT