Just gave it a quick test again and it comes to ~50 FPS, not 60 I must have tested it with the demo before. Using 400 now though.
Jedi, that does seem a little low. I think the culpret could be the K6-2, but what do I know, the last AMD I had was a K5 100
Just give it a try without your ISA card(s) - it would be interesting to see weather they slow your system down.