[--Steve-O--]

NAILED IT!!!

turns out it was a problem with either my debris, or destroyed engine models. i deleted them and popped the model back in game, full fire fight no crash, all three times.

still curious as to why debris or destroyed engine models would cause crashes.
even my non solid rotating section solidifed itself.
hmm.

[Water]

All the bits I've checked seem ok.
There are a few areas where you could reduce the poly count with out too much effort. (mainly in details)

The big turret has the only modeling error (that I've found - highlighted on orange) The turret also has polys that will never be seen in game. (The rear faces of the cylinder)

Also all gun barrels pointing down are shorter for some reason. It's as if all the bottom gun barrels were moved up, out of place ( I don't do model conversion, so don't know if this will have any effect)
I like the style of the ship 

[--Steve-O--]

thanks! i figured that much about the extra parts in the turrets, i was kinda affraid to merge the two parts, cylinder always seem to be a hasel for some reason, i've gone through and reworked those though. as for the bottom gun barrels being shorter, i never noticed it. i'll check it out though.
its good to know there aren't any catastrohpic geometry errors though, i was fearing the worst.
thanks for taking a look at it!