One might wonder how I noticed this, but it's in the wee hours and I'm skinning with a rage. All of a sudden I notice a single pixel column that's gone haywire when it was fine before. I search, search, search for the error in my bitmaps, can't find it. Then, I noticed that the same problem appeared with all the other skins! I switch over to netscape to write this, and when I came back, everything was fine.
The exact pixels were these: in the playlist, when one of the top-right buttons were pressed, but not clicked (e.g. you click on it but mouse the cursor away before letting go of the button), the redraw would shift the minimize (left) button to the right by 1 pixel. Weird, eh?