Sometimes 0.0005 is not enough, see:
https://en.bitcoin.it/wiki/Transaction_feesBlockchain.info doesn't know about the transaction id.
If something like this happen with bitcoin-qt, you can delete the transaction from the wallet.dat (with pywallet),
not sure if this is also possible with electrum. If that fails you could still export the private key
of the address with the coins and import it to mtgox or some other bitcoin client.
Edit: Yeah, there is an unconfirmed transaction now, but with another id, hope it's all good now