If you have Sega's PC versions of Daytona USA or Sega Rally you may find that every few seconds they speed up to an unplayably fast frame rate then go normal speed again, making them unplayable.

A fix (though this is weird) is to do Start->Run...->type: dxdiag

Leave dxdiag running in the background whilst you play these games and the frame rate will be fine! Totally odd. You don't have to disable anything in dxdiag either, just have it running!

Ice