The "split in half" credit file is a very real thing; it happened to me back in the mid 2000s. I had two credit files, both with the same name, SS#, DOB, address, etc. and some of my accounts were on one and some were on the other. There was nothing 'sketchy' going on, but it was a definite 'glitch'. When I would apply for credit it seemed random which report the lender would get. When I would request my report by mail I would get a printout of *both* reports, each with a different 'file number'.
I contacted the credit bureau by phone to get it corrected, and was told it was due to my having "so many old closed accounts and inquiries" and she insisted it was a "system contraint". I (politely) told the rep that their system constraints weren't my concern, and that I was entitled to a single, correct report. A few weeks later I received a new copy of my single credit file with all of my accounts showing. Apparently they were able to overcome their "system constraints".
If you do have a split file I would get it resolved sooner than later... it can cause issues down the road. (The worst case scenario is that it can be seen as fraud.)
