A strange thing happen to me today too. Maybe this is common, but it's the first time for me.
I withdrew .033 BTC from Coinex to my BTC address on Blockchain. It appeared right away, then disappeared,
then a short while after receiving the email below it reappeared again.

Transaction Confirmation Failed

A transaction made through Blockchain.info has been removed from our database because it was taking a long time to be included in a block.

Any funds have been returned to your wallet and you can now spend the coins again. Please consider including a larger fee in future transactions.