I had the same question just now and found the answer elsewhere

If your Bitcoin client is new or has been idle recently (e.g. not open), it has to catch up to the block with the transactions that you are concerned about before it is aware of them. So check the "x blocks" status in your Bitcoin client, and check the block # for the transactions you are looking for on block explorer. if your client's # is less than your transaction's #, then wait for the client to catch up. Once it does, it should show the transactions and be able to redeem the bitcoins. At least I hope so, as I am in a similar situation