I just ran into this problem today on my Dad's new computer. It's odd. It's a wireless mouse that runs through a dongle plugged into a USB port.
I can set the mouse speed (i.e., cursor speed) to be tolerable in Windows Vista by going into the control panel, selecting the "mouse", and playing with the pointer speed slider. But when I get into Aces High, the mouse movement is way too fast.
I know AH is just using what Windows gives it, as Skuzzy said, so it's some screwed up Vista thing, probably with different layers of code, with native being fast, then some higher layer of code taking the fast native input and transforming it into slower movement before you see it on the Windows desktop. Yet AH might be given something lower down before the translation? Who knows.
Ug. I'm new to Vista (don't have it at home). Vista devices seem to tend to have a blizzard of settings, different ways to get to the behaviour of the device, etc.
If I figure out how to fix it, I'll post the info here.