Same problem for me in Unity-2d in Ubuntu Precise 12.04.1 and Nautilus 3.4.2 ...
I found a workaround to recover the progress window: wmctrl
wmctrl -l List the windows being managed by the window manager.
wmctrl -a <WIN> Switch to the desktop containing the window <WIN>, raise the window, and give it focus.
Same problem for me in Unity-2d in Ubuntu Precise 12.04.1 and Nautilus 3.4.2 ...
I found a workaround to recover the progress window: wmctrl
wmctrl -l List the windows being managed by the window manager.
wmctrl -a <WIN> Switch to the desktop containing the window <WIN>, raise the window, and give it focus.
See wmctrl(1) - Linux man page http:// linux.die. net/man/ 1/wmctrl
It does the trick! But it is just a workaround!
I miss Lucid on that one....
ctrl-alt-tab does not work (nor alt-tab...) at all for me...