LibreOffice doesn't appear in alt-tab view

I have an annoying problem with Unity on Ubuntu: it often happens that LibreOffice/OpenOffice Calc or Writer windows don't appear in the alt-tab application switching.
Googling the problem learned me that it is a known problem: https://bugs.launchpad.net/bamf/+bug/1026426
The good news is that it is solved in Ubuntu 12.10, and a patch will be available for 12.04 LTS. A workaround is to restart Unity:

• Start a command window (Ctrl-Alt-T)
• Run:
  unity --replace & disown