When I try to switch between windows of a workspace using the Alt+Esc shortcut (cycle_windows key in gconf), the windows do rise up to the top, but this is accompanied by some other rendering artifacts, such as the corresponding window border being drawn at the wrong location with wrong size, rather than around the window, and also contents of other windows showing up within that box. Upon releasing the key, everything is fine, and the screen looks okay with the chosen window on top, but while switching, it's all a mess.