UBB 6.72 to vB 3.6.5 import errors

Greetings....

I'm receiving the following errors when I import the threads:
"got thread and DID NOT imported to the mysql database"
"invalid post object, skipping threadid" This was true with 3.65 and 3.64 with the lasted version if Impex. I don't have an old version to try.

The users and forums all imported fine. I have 20 forums. When the import thread runs, most of the first forum is completed when the errors start. After that, it's a never ending error display.

When I tested vB and Impex in Feb, all worked well.

Any ideas?

Thanx
Forrest