A few years ago I have done some transactions with BTC. Now I wanted to take a look at my balance again. It should be for about a little bit BTC but I only get a zero balance. The chain right now is up to date. I´m the owner of the address where it is - I´m sure and it is still always there. The backup I have made was 7 days after the last transaction of this wallet at a chain which was up to date at my PC (in the middle of 2013). Now, it´s a zero balance. The address which it´s laying on is NOT in my wallet, but I know it has to be there.

The difference between income and outgo say there is something. Maybe, the network has not submitted that it is there again?

Some solutions please. What´s wrong? What´s to do?