Sorry for the belated feedback.
The version you sent me a week or so ago seems to work flawlessly for me on my a1200+40mhz '040. I couldnt find a single problem or bug, and it's pretty much silky smooth, with the exception of rotating left and right, where there's a slight judder (only noticable though if a person is looking for imperfections).
The one thing I did notice though, is that reducing screensize makes absolutely no difference to framerate, and that "judder" when turning left and right is the same whether it's fullscreen, or a small window).