Are you switching monitor resolutions? I have an LCD so everything has to run 1024x768. Go into the game options and set the resolution the same as your desktop. NOTE: I think this only changes the resolution when you are in the game. The menus and the beginning of the scenarios may be fixed at 800x600. Try switching your desktop resolution and make sure your monitor is solid at 800x600.
(Are you on a PC? Then you have a bunch of other problems to look into ... directx is a morass of problems ... on the PC I had to turn off the music, and even then the resolution in the menus is messed up, I don't think it's changable)
It is a great game, IMHO, hope you get it working because you will love it.
If you tinker with the Jaguar text-smoothing settings (in the "General" pane in System Preferences), is the look of the text in Star Wars affected? Maybe Jaguar's text rendering is related to your problem.