There's too much crap in the model file... by crap I mean parts, I've regrouped the model to four parts and it's orbiting just fine ;) you need to play select and regroup in MS3D in order to get it right cuz my regrouping was a quick run and messed up mapping I guess, your best bet would be to select all parts that are mapped into one texture and regroup them to this texture, after that there should be about 35 regrouped parts and it will work fine.