I sent my coin to bittrex, after I pushed the send button the wallet went blocked for few seconds, after that the pop-up appeared, telling me that the coins has been sent. In about 1 minutes I saw the pending amount on bittrex. But after more than one hours my coin are still pending, and on my wallet I see Status 0/Unconfirmed with the "?" on that transaction. From the debug console I launched the command "checkwallet" and it give me the message are my coin missed? or they can't be confirmed for some reason? Solution?

Thanks.