have you tried backing up your .dat file and reinstalling it from scratch?
Yes,I have yesterday the same problem,I saw my wallet dat. file and config.file. After that I uninstaled my old wallet and downloading again wallet and put in roaming these saved wallet dat. file and config.file,and now running again.
Answer for the both of you -- Yes, I've tried that, download and run the new wallet again. It worked out well but isn't there any other way to solve it? I hope there is. This was my second encounter to the problem and it might occur again later on. Starting on scratch is a bit hassle, also syncing took so long in the new wallet.