Most likely you do own that address and your wallet wasn't open long enough for the incoming "change" transaction to confirm. IF you resynch it again now, you will probably see that tx in the log and have those BTC available to you.
Change addresses are generated from your private keys, and you won't see them as one of your pubkey receiving addresses until they are used for a change transaction.
oooohhhh
damn, I was confused when my blockchain said 0.06
BTC less then my wallet
![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif)
this explains it
![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif)