I withdrew a few BTC from an exchange into my Multibit wallet and the transaction appears on blockchain.info with about 50 confirmations but not in my wallet. I'd prefer not to publicize my BTC address here. What could be causing this?
This is probably an issue with the nodes that multibit is connected to.
Try closing and restarting multibit. If that does not work then reset the blockchain (twice if the issue is not resolved the first time).
If this does not work you should export your keys and input them to a blockchain.info wallet then send a TX to a new address in a new wallet in multibit (if you wish to continue using multibit).