I also have an issue with MultiBit on the Mac. I sent a small amount from one wallet to another with a fee and it still hasn't been confirmed 24 hours later. In fact, it shows up on blockchain.info: http://blockchain.info/tx-index/4e5da946e3d87c57c7c89f42b25bda54fcee9c497a8941e42c7836b56a4b3cc5


But it gives me a "no such transaction" error page on blockexplorer.com:   http://blockexplorer.com/tx/4e5da946e3d87c57c7c89f42b25bda54fcee9c497a8941e42c7836b56a4b3cc5

It was seen by 4 peers. It's certainly taking its sweet time to confirm... How long before I should be worried?