I realized today that there's another application that I'm having the same problem with. This application has two windows that I usually display in the same desktop. I realized that one of those windows was seeing the same symptom, and that it had probably been happening for a couple of days now. I restarted the application to get this window back.

I occasionally see a symptom where when I switch back to a desktop the window I expect to see there is not present, but it's still showing in the status bar (I have "keep all taskbar buttons visible" set). When this happens, I generally hover the mouse on the icon in the status bar, let the thumbnail appear, then right-click on that and select "Move". It appears that I have to press at least one arrow key at this point, then I can drag the mouse and my window appears from off screen.

This is annoying when it happens, which I see a few times a day.

However, at this moment I'm seeing a situation where my Eclipse window simply isn't showing up in the preview window or the status bar. Every single time I move to the desktop where I expect to find Eclipse, it's not there, so I use the aforementioned technique to get it back. However, Dexpot still doesn't know about it, so when I move away and come back, I have to do this again.

I thought perhaps I could hack this to work by exiting Dexpot and then reentering. However, that only made it worse. Now, when I right-click on the thumbnail from the status bar, the thumbnail goes away and the menu doesn't appear. I thought there was another workaround I could use at this point, but I don't remember it. It looks like I'll have to remotely kill the Eclipse process and restart it.