Ah, OK. Yes, moving the top panel to the bottom makes the gap go away. And contrary to what I expected, no new gap at the bottom of the rectangles emerges. So it seems to be a bug in the handling of panels at the top.
-- [edgy] Workspace switcher: Maximized windows have one pixel gap https://launchpad.net/bugs/60447 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
