Well the wallet let me send them, but the transaction hasn't gone through. I was trying to send them to hitBTC, any ideas?
You should not try to send them using the old wallet. It will not work. Try to do what
uralcryptocoin suggested:
You can run the old wallet and back up your private keys (you do not need to sync it just backup private keys) and try to import them to the new one
Will it work even though I've now sent them, or are they lost? is backing up private keys the same as backing up wallet.dat?