As you might be aware, there have been recently an attack to bitcoin network using a small flaw in the bitcoin protocol. This does not compromise your or anyone's else bitcoin funds and the protocol itself is not compromised, but it has affected lots of unsuccessful transactions. You can read more here.
As a reaction to the circumstances we have made changes to withdrawals: Transactions are processed now twice in an hour. This means that your transaction will be broadcasted 0-30 minutes from the moment you initiate it. However, this does not necessarily mean that outgoing transactions are selected by order due to some technical limitations. Therefore you might experience some delays when sending transactions outside localbitcoins system.
When checking whether your outgoing transaction has gone through, please copy the address you were sending your bitcoins to, and go to https://blockchain.info/ and insert your address to the search box. If you are able to see the transaction in that address with same amount, the transaction have been successfully conducted. If your transaction is neither in "Pending" status or it has not been received any confirmations, please let us know.