Just purchased C8pro, bringing in my files from C5

I have a staircase Ive been building most of the components map just fine, however the railing maps just fine ( I check it with a checker pattern) until C8 is saved then reopened. Its as if C8 is remapping the obj all by itself and infact thats exactly whats happening. If I export the railing back out as a obj and check it with my uv software it has indeen been changed. I bring the railing into ZBrush and its just fine. Im a fairly experienced mapper, but this has me stumpped.

Why would C8 alter the mapping of an item when saved and reopened. I work with ZB, Poser and C5 for years, Ive never seen this before.

Any Ideas?