I've played extensively with Spaces. Today I had 4 Spaces, with multiple Safari windows and multiple TextEdit windows open in Space #1 and in Space #3. I moved back an forth quite a bit, but then spent some time opening and closing windows only in Space #1, finally closing all Safari and TextEdit windows there. When I pressed F8, Space #3 had no windows open! In the Dock, Safari and TextEdit were active. If I clicked either of them in the Dock, I'd switch to that application's menus and see my windows from Space #3 listed in the "Windows" menu, but the window would not actually appear anywhere in any Space if I chose it from the Windows menu. The same with control-clicking in the Dock; the windows were listed, but would not display. The windows for a separate application I had open only in Space #3 were also gone. I hadn't used them in any other Space. I tried control-click-Quit on TextEdit in the Dock, knowing that I should get a "Do you want to save the changes?" prompt. It played the alert sound but showed me no TextEdit window or prompt. I couldn't view my window, save it, or Quit without saving! There seemed to be no clean way out, until I tried collapsing all windows into Space #1 (by pressing F8 and then C) and then disabling Spaces in System Preferences. Instantly, my missing Safari and TextEdit windows reappeared in Space #1. My windows from the other application are back too. I re-enabled Spaces and everything seems back to normal. Has anyone had a similar experience? Does anyone have any theories?