I have never seen this before and I don't understand what's going on. I received a payment almost exactly 3 hours ago as of now. My Bitcoin client says it's up to date, in sync and connected to 15 active connections. Yet this payment received 3 hours ago says it has zero confirmations. How can this be? How can I fix it?
My debug window says that the last block I got is 266592 which agrees with what blockchain.info is swaying the latest block is right now.
Was a sufficient fee included with the transaction? If not, it can take some time before it gets confirmed.
Post the transaction-ID and/or a link to the transaction on blockchain.info so we have some more details.