Why does blockchain.info show the warning "Transaction rejected by our node. Reason: The transaction is not final"? The transaction fc3f81c625720063c5cab2145bcb5ef20b13ff0aa73b0b2435ffdb645acfcb8b has the warning "Transaction rejected by our node. Reason: The transaction is not final." on Blockchain.info.

The same transaction shows up with five confirmations on Blockexplorer.com.

What does that "the transaction is not final" mean, and why did blockchain.info reject the transaction?
BTCJerk on reddit noticed that "Blockchain.info is having issues, the last block they show is 442341". Other block explorers were already on block 442349…

Since the transaction was timelocked until block 442345, and timelocked transactions are considered invalid until the appropriate blockchain height is reached, blockchain.info was still considering the transaction invalid due to its lagging behind.