Occasionally MultiBit may seem to be stuck. You may have transactions that don't appear to confirm (even though you can see that they've confirmed by checking on Blockchain.info), or MultiBit may say it is synchronising for a long time. You can use "Repair wallet" to reset your block chain and get unstuck.
From the Tools select "Repair wallet" and select "Next"
The repair wallet process gives MultiBit the opportunity to revisit old transactions, and check if a transaction has fully confirmed. If the transaction has confirmed, then it will appear in your transaction list.