Arr, im running x86-64 gentoo with a 2.6 kernel, and while fullscreen the fps is fine, if I run it in windowed mode its absolutely horrid, updating the screen a little less than once a second or so. This is with xorg/xfce4. Im fairly sure this is related to something in vendetta, as the various unreal tournament and doom games, etc all run fine in a window.

Perhaps your Voodoo Banshee just can't keep up :)

On a more serious suggestion: Could it be colour depth related?

Yeah, what is your X color depth and what is your VO colordepth?

good point. I shall have to check it out.

[EDIT]

hmm, both 24.