I'm having exactly the same issue with Fallout 1, running the latest high resolution patch, at various resolutions and colour depths.
I have tried speeding up the mouse sensitivity in the game preferences, deleting the ddraw.dll, and disabling the option "Use OS native drivers for pointer speed and acceleration" in my SetPoint settings.
I am using a Logitech mouse on Windows 7 64 bit and the pointer only becomes sluggish near the buttons. Otherwise it moves smoothly.
Any further advice would be appreciated.