IIRC, all those ATi Users (me at work included ) get either 8, 15.x or 32 fps .. so it looks to me as if some strange sync thing is going on.
This would be either a SDL or a Dom2 issue .. did you ever contact the SDL developers about this?
__________________
As for AI the most effective work around to this problem so far is to simply use an American instead, they tend to put up a bit more of a fight than your average Artificial Idiot. ... James McGuigan on rec.games.computer.stars somewhen back in 1998 ...