I don't have Lion myself, but could you paste the contents of the crash report here? Unless it has changed in Lion, when an app crashes under OSX you should see a frame telling you that the application crashed with an option to see the crash report
Okay, so interesting update. I tried out v0.1 and fullscreen works. However, all games except for Goldeneye exhibit rapid flashing and other glitches and garbage. Are there graphics configurations I could try? Any idea why Goldeneye works, but the other games don't?
To Anonymous above: Try going to Plugins and selecting mupen64plus-video-glide64.dylib as the Filename of video plugin.
To Marianne: any update on the fullscreen crash for v0.2 in Lion? I too am experiencing the same as above. Thanks for all your support!
I haven't found the problem at this time since I don't have Lion. However you can go in the plugin options and select external video as videoExtension, this should fix this issue and hopefully won't create others