If "Autohide" option is set for the Panel, dragging windows between workspaces using the Workspace Switcher does not work. When I press left mouse button a small window icon with an arrow appears, but the Panel gets hidden, and you have no place to drop the icon (unless I do it really very quick). But if I drops it anyway within the Panel boundaries, the Workspace Switcher just locks up - I cannot change the workspaces anymore.