I recently upgraded to Ubuntu 10.04 Alpha 3. A few days ago Ubuntu announced a new branding. One of the things they changed is the order of the window button layout. Instead of the expected Minimize | Maximize | Close they changed to Maximize | Minimized | Close. Very confusing and I kept pressing the wrong button each time I wanted to maximize my screen.
Luckely there's an easy way to alter it. Open the Configuration Editor, navigate to /apps/metacity/general and modify the button_layout key to:
menu:minimize,maximize,close