Losing stuff while converting FSDS to Gmax

I tried converting my FSDS project to Autocad, and then to Gmax, but somewhere along the way, I lost the interior fuselage of the aircraft. Is there any way I could have prevented this? Both pieces of fuselage had been joined, and both showed up in Autocad. Also, the exterior pieces I added in the same manner as the interior are still there. What gives?
Also, may I suggest the method of converting between the two be added to the faq at the beginning of the forum?


Also, may I suggest the method of converting between the two be added to the faq at the beginning of the forum?

