Blank screen on startup

When I launch Uplink my computer thinks for a moment, then switches to a grey screen where I can't do anything and am forced to restart. I've tried 1024x768 and 832x624 resolutions and get the same results. I have a Radeon Mac Edition video card, over 140MB of available memory, and am running OS 9.1. All of the required extensions stated in the FAQ are up to date. My computer is a little slower than the stated requirements, but I think that would only cause Uplink to slow down rather than not work at all. If you have any ideas please let me know.