During the lunch break of my interview, we had a few dental students with us....one of them has been having a lot of trouble getting instate tuition and the other one received residency before classes even started....they both bought property, but the only difference was that one had an out of state co-signer and the other one didn't...
I'm not sure if that makes a difference, but they seemed to think it was the only difference....moral of the story: it can be hit or miss when it comes to getting residency (and don't have an out-of-state co-signer)