@hangar18
Hello,
I'm not familiar with that product but the symptoms you describe might be related to the direct x files themselves. Inside a Direct X file are a series of templates or code blocks that tell direct x how to construct your object. DBC uses Direct X 7 I think and today's standard is at least direct x 9. There could be templates that DOGA puts in or leaves out of the Direct X file it creates that may not be 100% compatible with DBC and how it uses Direct X 7.
Try downloading the free version of Deled and import your DOGA x files into there and then export them back out. DBC is compatible with the Direct X files that Deled creates. If these converted files load into DBC, that will at least give you a clue it's probably DOGA's export that is the problem.
If that doesn't help, if you want to attach a copy of one of your models to a post, if I have time, I could take a look at it and maybe tell you what the problem with the X file is.
Enjoy your day.