Fascinating.
When playing a copy-freely program, the Aero Peek mini-thumbnail is an "active" miniature of the real WMC window. You see what's playing, live, in this little mini window.
But when playing a copy-protected program, there is simply a Green Button WMC logo in the center of the mini-thumbnail. I don't understand why that makes sense, since the program is currently playing in the real WMC window. What could possibly be the reason why it's suppressed in the Aero Peek thumbnail?
Never noticed that before tonight.