I did think it very odd that you had them in the wrong format - I was pretty sure you'd been making them correctly for a good while now, but didn't have time to check for sure.

Anyway, I *think* this error can be caused by wonky vertex normals rather than face normals (which would make the face invisible if they were on the wrong side) - so it might be related to the smoothgroup problems I suspect the max exporter has. That said though, did you actually use the max exporter in this case or was it via a DAE?
Also, Taylor - do you remember where abouts that problem occurred on the Faustus? It's since been reconverted for the next MVPs to fix a number of other geometry issues it had, so I'd better check the new one for that sort of thing when I get home tonight.