when Bitcoin hits ver1.0 I think it might be ready for non-programmers
in the mean time it is beta software and should be treated as such

oh and I'm not a programmer, the last bit of coding I did was on punchcards at highschool lol. but I have been involved in Bitcoin for around 18months now, a lot of stuff is easier now than it was

You can see the transaction here:
http://blockchain.info/tx-index/15473291/c8bfd253ec0c028087f40bb8df61a1dd4167ed2acb0519e68e6d87bc174035731) You own the private key to bitcoin address 17dhPor26EjpkcRuEWgzBJPzXuTP9UT1jo which had received 8.7642 BTC on 2012-08-09.
2) On 2012-08-12 you asked the client to send 0.0003 BTC with a 0.0005 BTC fee.
3) The client chose to use the coins from 17dhPor26EjpkcRuEWgzBJPzXuTP9UT1jo for the transaction (the current client doesn't allow you to easily choose which address to send the coins from).
4) The client created a transaction that sent all 8.7642 coins from 17dhPor26EjpkcRuEWgzBJPzXuTP9UT1jo (used 8.7642 from that address as the input for the transaction).
5) .0003 of that 8.7642 was payed to the destination address that you chose: 1K563Jeki3qtJrfv8BR6LLeG1ioK13K3td. If this destination address is in your wallet, then the 0.0003 coins never left your wallet, they just moved from 17dhPor26EjpkcRuEWgzBJPzXuTP9UT1jo to 1K563Jeki3qtJrfv8BR6LLeG1ioK13K3td.
6) 8.7634 BTC of the 8.7642 was payed to a new address that the client added to your wallet, 1KjbJv3gp1MS7mamPgC8KmPf57rGqiwyvi. This isn't an address that you created to give to others for them to send coins to you, so it doesn't show up in your "receive coins" tab. But it is an address hidden away in your wallet. In the future when you send coins, the client can choose to pull coins from this new address. Since this destination is in your wallet, the 8.7642 BTC also never left your wallet, they just moved from 17dhPor26EjpkcRuEWgzBJPzXuTP9UT1jo to 1KjbJv3gp1MS7mamPgC8KmPf57rGqiwyvi.
7) Any remaining coins from the input are kept by the miner that created the block with this transaction in it. In this case 8.7642 - (8.7634 + 0.0003) = 0.0005. Therefore the miner gets to keep 0.0005 BTC from this transaction. In this case that would be the person who owns the address 1Baf75Ferj6A7AoN565gCQj9kGWbDMHfN9, as can be seen here:
http://blockchain.info/block-index/260167 These are the coins that actually left your wallet and show up in the "transactions" tab in the client.
Thanks for the detailed explanation. I wish I could see the current balance in my wallet for every address (including "hidden" addresses). I think that would have cleared up a lot of the confusion for me earlier on.