Confirmations on sent/receive transactions, still have 0 balance
It is possible if the client crashed it didn't finish processing the block containing your transaction (due to bad timing) and now that it is past that block doesn't go back to "double check".

https://en.bitcoin.it/wiki/Running_Bitcoin

There is a command line argument -rescan which forces the client to recheck every block for transactions related to the current wallet. In windows it would be done from Command prompt "bitcoin -rescan".  I assume OS X has some sort of commandline option.

Alternatively you can stop the client.  Make a backup of your wallet.dat.  Delete all the files from bitcoin configuration folder other than wallet.dat file.  Restart the client.  It should show 0 blocks and not have the "bad transaction".  The client will download the blockchain. This could take an hour or more.  Once block chain is fully downloaded the transaction should appear and balance updated.