Boot into 11.04 with single laptop monitor (Dell Latitude D830). Suspend okay on lid closing. Open lid with external 1080p monitor connected. Many windows have apparently disappeared from the display (4 desktops) but can eventually be found almost off the screen on the left-hand side, a mere 10 or so pixels wide. They have to be dragged back onto the display with ALT-F7 and can then be resized using the mouse. Other windows have just "gone", and I have to kill their PIDs before I can restart them from the Unity toolbar.
Under Ubuntu 10 I had no such problems, looks like a Unity issue. Any solutions apart from regressing to Gnome 2?