I made a model in wings 3d and exported it a .x file.
I then try to load it using max and the mini3d module, all I get is a spinning cube.
It loads .b3d files. In the code archives is a blitz3d source code that converts from .x to .b3d
Models which can not be loaded by minib3d appear as cube.
I recommend fragMotion for converting any of your models to B3D format. It should be able to do anything you want it to (regarding modelling, that is. It can't make toast.)
http://www.fragmosoft.com/:)