Make sure you freeze all transforms before export.
Make sure you freeze the model before export.
Make sure you have everything de-selected before you export.
Definitely did all this, as instructed by Ironclad's documentation.
Open up your .xsi file that you have just created and check whether the info is in there before you converted to mesh. The info is set out a bit differently but you should be able to find vertex and triangle count. If they are 0 in the xsi file also it means that you only had your nulls selected when you exported.
XSI by default should export everything in the scene if everything is deselected. Shift+Ctrl+A should deselect everything, though sometimes I'm sure this doesn't work for some reason.
You can either try exporting it again. Do Shift+Ctrl+A several times before exporting, and it should work(should).
Or you can select everything that was missing in the first export by selecting them in the scene root (press 8). Then export with those selected. Then paste in the point info from your first export file to complete it. I usually do this after they are converted to mesh. because I am more familiar where things are supposed to be with mesh. files.
Additionally you could try selecting every thing under the scene root (press 8) and then export.
Hope that helps some.
Okay, well I went through all of your suggestions and tried them, and nothing worked. And then suddenly I had an idea.
It turns out my problem was that I was using Softimage 2011 demo instead of Softimage Mod Tool. Apparently the newer software does things differently. So now I can get the model in-game, all meshpoints fully functional, but now I'm having another problem.
The textures seem to be applied properly to my ship, but for some reason my in-game player color is almost completely blanking them out. The entire ship is a bright glowing blue, but you can see the textures underneath if you look closely enough. Anyone know what this means?