I tried all the fixes suggested, and though the scrolling problem is still there, at least it's been isolated.
The scrolling bug happens whenever I play <img src="/ubbthreads/images/graemlins/beyond.gif" alt="" /> , save and exit the program, play something else, run a few other applications, and then try to run <img src="/ubbthreads/images/graemlins/beyond.gif" alt="" /> again and load a saved game.
Rebooting is the only thing that seems to clear this up, and it works every time. I don't suppose it'd be possible for <img src="/ubbthreads/images/graemlins/beyond.gif" alt="" /> to clean at startup whatever relevant files a reboot cleans?
I'm running Windows XP Home Edition, fully updated, and have a standard Logitech keyboard and optical mouse setup with none of their extra software installed.
-F.