I've got this weird thing happening: I stuck a model, models/map_objects/imperial/cell_door_frame.md3 (the cell door frame from Dossuun) in my map, and it comes up fine in Radiant, but when I run the level in JA the model is completely dark. I've tried messing around with lights and the various bsp options, and I've tried using the other cell_door models, but they all refuse to display properly! All other models seem to be ok, it's just these ones.

Try using light_juniors or alter the shader code (the shader being the reason why the model's not lighted).

or use a misc_model_static, it worked for me (bacta tanks)

Misc_model_statics get no lightmapping at all, but if that's no problem, then it's certainly one solution.