My account's wallet address was changed to 19Shfvxg2itN724sE5QHDzboC3v9Zymqa3 with no wallet change notification email or payout lock activation. (Payout lock will activate for 24 hours if your wallet changes. ) I hit the payout button before I noticed the change.
My email account and computer have not been compromised so I don't know how or why it was changed.
The address listed on my bitcoin client is 16PeQzubA2YvaepFeAcP96SryY73nLySJY.