Launcher does not show on "Show desktop"

There's nothing in that screencast

What do you mean by "nothing"? It clearly shows that after minimizing all windows Unity stays hidden, where it should show up (there's no reason for it to hide, as there is no window open and there is nothing underneath it on the desktop).

Status changed to 'Confirmed' because the bug affects multiple users.

Hello sabby7890, or anyone else affected,

Accepted unity into oneiric-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

I can confirm this to be fixed in the proposed version of Unity.

This bug was fixed in the package unity - 4.24.0-0ubuntu2

---------------
unity (4.24.0-0ubuntu2) oneiric-proposed; urgency=low

  * Cherry-pick upstream:
    - SRU0-Regression: scrollbar displacement caused dash rows to show less
      icons (LP: #875023)
    - Really reverts the UI change that was still uploaded even if we had
      reverted it…

unity (4.24.0-0ubuntu1) oneiric-proposed; urgency=low

  * New upstream release and some cherry-pick:
    - compiz crashed with SIGSEGV in PluginClassHandler<UnityWindow,
      CompWindow, 0>::get() (LP: #864758)
    - unity panel menus don't stay open when clicked on second monitor
      (LP: #869196)
    - (oneiric) menu bar in wrong place and invisible (LP: #845856)
    - Lens range widgets do not function correctly (LP: #862996)
    - Cannot raise window from panel after minimize (LP: #863114)
    - unity-panel-service crashed with SIGSEGV in g_closure_invoke()
      (LP: #843280)
    - Windows get corrupted sometimes when semi-maximizing them. (LP: #865177)
    - Automaximization happens on unminimize (LP: #868930)
    - compiz crashed with SIGSEGV in nux::ROProperty<std::string>::operator
      std::string() (LP: #869109)
    - Dash - horizental divider line in between categories incorrectly drawn
      (LP: #841750)
    - F10 opens a random menu item when it should open the first one
      [regression] (LP: #862849)
    - Switching desktops after using showdesktop can cause hidden windows to
      become "active" (LP: #864503)
    - Clicking blank space on top panel doesn't raise maximized window to
      front (LP: #864708)
    - unity launcher loses track of deja-dup windows (LP: #865051)
    - Dash - App Lens 'Rating' filter behaves incorrectly (LP: #865482)
    - Launcher does not show on "Show desktop" (LP: #867959)
    - ibus character selection window not drawn (LP: #867885)
    - the dash's entry get wrongly colored on left or right key use
      (LP: #868434)
    - [ibus] Pressing down when ibus is active moves focus (LP: #872730)
    - Double-click on the dash top panel is taken effect on the window
      underneith (LP: #870844)
 -- Didier Roche <email address hidden> Tue, 18 Oct 2011 12:47:54 +0200

This bug was fixed in the package unity - 4.24.0-0ubuntu2b1

---------------
unity (4.24.0-0ubuntu2b1) oneiric-proposed; urgency=low

  * No-change reupload because of broken powerpc build.

unity (4.24.0-0ubuntu2) oneiric-proposed; urgency=low

  * Cherry-pick upstream:
    - SRU0-Regression: scrollbar displacement caused dash rows to show less
      icons (LP: #875023)
    - Really reverts the UI change that was still uploaded even if we had
      reverted it…

unity (4.24.0-0ubuntu1) oneiric-proposed; urgency=low

  * New upstream release and some cherry-pick:
    - compiz crashed with SIGSEGV in PluginClassHandler<UnityWindow,
      CompWindow, 0>::get() (LP: #864758)
    - unity panel menus don't stay open when clicked on second monitor
      (LP: #869196)
    - (oneiric) menu bar in wrong place and invisible (LP: #845856)
    - Lens range widgets do not function correctly (LP: #862996)
    - Cannot raise window from panel after minimize (LP: #863114)
    - unity-panel-service crashed with SIGSEGV in g_closure_invoke()
      (LP: #843280)
    - Windows get corrupted sometimes when semi-maximizing them. (LP: #865177)
    - Automaximization happens on unminimize (LP: #868930)
    - compiz crashed with SIGSEGV in nux::ROProperty<std::string>::operator
      std::string() (LP: #869109)
    - Dash - horizental divider line in between categories incorrectly drawn
      (LP: #841750)
    - F10 opens a random menu item when it should open the first one
      [regression] (LP: #862849)
    - Switching desktops after using showdesktop can cause hidden windows to
      become "active" (LP: #864503)
    - Clicking blank space on top panel doesn't raise maximized window to
      front (LP: #864708)
    - unity launcher loses track of deja-dup windows (LP: #865051)
    - Dash - App Lens 'Rating' filter behaves incorrectly (LP: #865482)
    - Launcher does not show on "Show desktop" (LP: #867959)
    - ibus character selection window not drawn (LP: #867885)
    - the dash's entry get wrongly colored on left or right key use
      (LP: #868434)
    - [ibus] Pressing down when ibus is active moves focus (LP: #872730)
    - Double-click on the dash top panel is taken effect on the window
      underneith (LP: #870844)
 -- Martin Pitt <email address hidden> Tue, 25 Oct 2011 07:01:51 +0200