So, really weird. Went to send some bitcoins to another of my wallets and all went as expected. I sent 1.013 BTC from a balance of about 3.01254367 BTC. My girlfriend then went to make a withdrawal. She said the balance was just over 4 BTC before the withdrawal which it couldn't have been because of my last transaction. It should have been just over 2 BTC. She said she sent 4 BTC leaving about 0.5 BTC in wallet. The transaction stuck, that was when I got involved to sort it all out!
I reset the blockchain and transactions on multibit and now the balance is 0.97 which doesn't seem to match up with anything? The transaction has shown up on the blockchain at all but I'm down by about 1 BTC.