Unconfirmed Transaction disappeared when I pressed "repair wallet" I bought some bitcoins and send them to an a receiving address on Multibit HD, It has been maybe 3 or 4 hours without any confirmations, so I decided to press "repair wallet", which said it would resynchronize etc.

Now the "+Unconfirmed transaction" bit isn't even showing anymore and it isn't in the payments section. Here is the bitcoin transaction:

https://btc.blockr.io/tx/info/111df2572b8550724c78f30bf70f4cafee61417924058fdd624adb172968637a
That transaction looks fine so try the Tools | Repair wallet again to see if it appears.

If that does not work then you can 'clone' your wallet in Lighthouse using your wallet words and see if it appears in that.

Lighthouse and MultiBit HD use the wallet words in the same way.
https://www.vinumeris.com/lighthouse