The reason I originally had them like was when I first installed X2 it was seriously dropping out, so had to bump them up. I have since done a format and fresh install of everything, not sure if something was originally conflicting with X1 or something else, actually Ive just tried them at 256 seems OK now! :-)
Although I don't remember changing them this time around? would wave profiler change them when it runs?
I had quite a few problems with X2 prior to a fresh install.