Minimizing a window makes it inaccessible.

[Peter Lesterhuis]

>
>
> After an update to X11 I had some errors in the
>gnome desktop, and canceled the restart of some items
>when they failed to start.
>
>     Since that time I find that when I minimize a
>window, I can't get it back again.
>
>     Does anyone have any ideas what I need to get
>started again?
>

Right-click on the bottom panel, select "add to panel", scroll to 
"window list", click on it and press "add".