When a pixmap or SVG theme is used and Gnome's panel is not fully expanded, the edges look ugly - as if the pixmaps are not being placed properly. Take a look at this screenshot, where the arrow is pointing. See the little black bar on the right side of the panel?

This disappears if I tell the panel to use a specific color instead of the system theme, but that of course poses its own problems. Is there another known workaround for this bug?