Ahhhh, I think I may have (along with others that have mentioned it before) the answer to whats causing the problem. Bad news is, there is no way to fix it as far as I know.
Follow me now. I have 76 Premium cars. I thought that I had deleted them all the last time I did this but I ended up missing them because they did not have any thumbnails and I must have passed right over them. They are two NASCAR cars. Anybody want to hazzard a guess as to whats wrong with them, besides the thumbnail thing. I can't delete them, use them, or do anything with them. They also lock up my system when I try to "create thumbnails for all cars". My system is locked up right now because it was creating the thumbnails, got about halfway thru, and froze. And I'm guessing it froze when it got to one of those undeletable/unusable cars.
Others that have this looping issue, have mentioned that they too have these cars. I think because of the PP update, it is getting stuck in the loop because it can't update the PP value of these cars.
I am almost willing to bet that if there is a way to delete these cars, everything will work fine. Thoughts..................