Having the tx in limbo prevents me from doing anything else to resolve it.
Is it possible it went to the deposit address for another BitFloor customer and thus never hits the blockchain?
Since you can never prove the funds were sent in this instant, it is probably best to withdraw to your own wallet first. Sure it takes one confirmation (or use a fork that doesn't require that) but then if this "internal transfer" is what happened in this situation, you'll never run into it again.
Mt. Gox withdrawals have the "Open transaction" flag which, if the checkbox gets marked, causes the transaction to always hit the blockchain, regardless of whether or not it is to another Mt. Gox account.