Hi, i started having this problem when i run the -server option too. It happens when the computers are turned off unexpectedly. I have four mining servers and at first just one was affected, so I just pointed cgminer at the other server which was working, but now all of them are affected so I am forced to find out whats causing the problem. Once I figure it out I will post it here.
This is what i have tried so far with no success:
Delete all files from the bitbar folder in the appdata directory (make sure you make a backup copy of wallet.dat before doing this)
Delete the bitbar-qt.exe folder with all files.
This did not fix the problem. Will keep you posted with my progress.
Cheers Santa, I tried all that too, also with no luck. Keep us posted!