After I get my staking,I close the client.When I open the client again,it shows my stak was not accept and my 450 kore disappeared. neither in the stake balance nor my current blance.
What happened?

Status: 0/unconfirmed
Date: 2014-06-15 21:24
Debit: 0.00 KORE
Net amount: -450.00 KORE
Transaction ID: 3bf4c435a4157faf7ef09ab0804600c2f1bcd8520cb7170bf263230437489bf9
Generated coins must mature 50 blocks before they can be spent. When you generated this block, it was broadcast to the network to be added to the block chain. If it fails to get into the chain, its state will change to "not accepted" and it won't be spendable. This may occasionally happen if another node generates a block within a few seconds of yours.