Mechwarrior 4 help

[SkaGoblin]

When I use my mechwarrior disc, it installs fine and plays the opening movie fine. I can do the mech lab, and all is fine and good. However, if I try to do anything outside the menu, like actually play the game, the game dies and gives me a STOP: This is not a database! I've tried the patches from the site as well as unsafediscing the exe and I get the same error. Any help?