My wallet has been out of sync for the last 14 hours since it staked some POS blocks. Restarting the client hasn't help yet...
Hopefully, you'll get this sorted out.
-tb-
Same thing happened to me.
POS staking needs to be blocked until the client is fully synced.
Make a copy of your wallet.dat and delete everything in your appdata/roaming/ADT folder and redownload the blockchain from scratch. Once fully synced, use the repairwallet command in the debug window to discover any erroneous balances and your coins should now stake. Your balance will likely show in the unconfirmed stake until the minting process is done.