If you only have a single output received in the wallet, then when you send bitcoins, the entire output must be spent. The wallet creates a single transaction that spends that previously received output and creates two new outputs, one to send the bitcoins where you want to, and the other to send the "change" back into the wallet. This means that the wallet doesn't have any outputs that are confirmed until that transaction is confirmed, and therefore the balance is "pending".
Ah ok, So its a new feature then.
Nevermind finding the bugtracker then.
Thanks for the heads up on this.