Ok, heres what i'm getting. There are 6 (pos/neg) boolean groups. I convert all seperatly.
I then select all the other single elements, make them positive and group them. The I convert that group.
After I have export and check the model, it only contains the 6 (pos/neg) boolean groups and a small section of the other elements.
Tried this with .3DS and .OBJ, same thing happens.

Any ideas?