I’m seeing this in both 6 and 7 (I’m using increased contrast but the artefact exists also in normal display). The right edge of the buttons are not drawn.
Can you explain how you got the UI into this condition. When I try here I’m not able to make the controls clip in the way that you are experiencing.
The only thing I’m aware of doing is check “Increase contrast” in the Accessibility > Display panel of System Preferences. But even when I uncheck it I don’t get a satisfying result. Weird.
