We just got a new Mac Pro (8 core 2.4Ghz Westmere 24GB RAM, 4x2TB Hard Drives - running Snow Leopard) and our copy of Scratch is running slower than on our 5 year old iMac (without even cuda cards)! It should be lightning fast. We are sitting around waiting for the little spinning cursor for even the most simple of calculations or even changing interfaces.
The startup screen shows that it is seeing our two GTX470 Nvidia Cards, no problem (updated to the latest drivers - same as quadro 4000 for Mac). "Hardware Monitor" shows both cards are fully functioning and the cores appear to be active. No idea what's going on.
Scratch has mysteriously started working correctly again, however I find that it takes a tremendous amount of dragging to move the curves. Nothing like the speed on my little iMac. They move, but it takes a tremendous amount of dragging to make a large change. Everything else seems to be functioning pretty well. Very strange.