This problem still has my curiosity - I'm going to import one of the raynor or titan multipart missile turrets, and try and put it on the side of the Orion.
That way, we can isolate the source of the problem (hopefully). If it's just a buggy multipart turret model, then if I understand you correctly, importing any other (presumably non-bugged) multipart turret should work.
Anyway, onto more grand and spectacular things...
In one mission, I'm going to have a ship explode upon entering subspace, while it is halfway through the subspace window. The 'cause' of the explosion is supposed to be the front end of the ship being shredded and ripped apart by violent distortions in subspace.
Would it be possible to make a custom subspace window effect for this? Is it like the shockwave.eff file, with all the .dds image files to go along with it? Or is it a .ani file (and if so, could someone plz point me to a program that can open, edit, and save .ani's easily?) I imagine replacing the existing one entirely with the new one would not be monumentally difficult - but I will only need to use this 'special' effect a couple times over the entire course of the campaign.
Similarly, would it be possible to change the shockwave used, when the ship explodes? I already plan to use a seperate ship in the ships.tbl file, with an instantaneous explosion, rather than lingering around and exploding a few seconds after the hull integrity reaches zero.
Also, I read somewhere that it was possible to spawn weapon projectiles into a mission, via a SEXP. Is there a tutorial on this somewhere? I'm considering using it to generate a 'spray' of projectile-debris, in front of the subspace window - assuming that drawing that many projectiles on the screen at once won't make peoples' PC's melt down.
The Shivans are going to use a wide-area subspace disruptor, left over from an eons-old war. It's essentially a galaxy-wide endgame device, instantly blowing up any ship that enters subspace. Subspace stabilizers on Shivan ships negate the distortions in immediate proximity to them, allowing them to move about freely. If the battlegroup the player is travelling with did not have access to captured Shivan ships, this would effectively have been the end of the GTVA, and the extermination of everything in the galaxy that's not Shivan.
Yes, I have watched too much Stargate Atlantis