Help to deal with the problem: I'd like to understand what happened - theft BTC or system error.
On the purse was the amount 12,89 BTC. When opening the wallet has failed, in which the wallet started synchronizing with the first block. After synchronization is complete, the balance of the purse 0,0009 BTC, there are two transactions, which I did not commit, to unknown address 1MbDKqngwKQ49TowToHGc9nZBRt99CqK8т on the amount 12.8 BTC and 0,098 BTC.
How to determine: whether this address is the address of my wallet and not visible due to a system error, or the theft occurred, and this address belongs to a thief?
If this is a bug, what can I do to return BTC?