It could be there is something major wrong with the house that doesn't show from the curb. Or that it is a teardown and the new owner is working on getting a new building approved. Have you checked with the city's inspection and/or planning department?
Did the bank get it back in foreclosure? Ask the new owner, not us!
I had a similar situation happen to me. It turns out the property was sold back to the bank after changing owners a couple times. So I had to go directly to the bank.
PM me the address if you like, I will take a look and see if I can tell you anything else about the property and/or owners.