launcher can not be revealed using mouse

Bug Description

This happened after dist-upgrade this morning.
I'm unable to reveal launcher using mouse any more. No matter how hard I try, launcher just doesn't show up.
The only way how to access the applications is keyboard which is extremely inconvenient (when I press the super key, dashboard together with the launcher show up so I can workaround it this way).

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.6.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic-pae 3.2.9
Uname: Linux 3.2.0-18-generic-pae i686
ApportVersion: 1.94.1-0ubuntu2
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,resize,snap,regex,vpswitch,imgpng,unitymtgrabhandles,gnomecompat,place,mousepoll,animation,grid,move,session,workarounds,expo,wall,ezoom,fade,scale,unityshell]
Date: Tue Mar 13 08:23:33 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2012年02月17日 (24 days ago)

I can not reproduce any more and I'm not exactly sure what happened.
I tried the following:
- using "dpkg -i --force-downgrade" in /var/cache/apt/archive I tried to downgrade to unity_5.4.0+bzr2065ubuntu0
- after the downgrade I logged out/in and I was still able to reproduce the but
- gave up and run dist-upgrade again to go back to 5.6
- had to manually resolve some dependency issues (for some reasons libunity, unity-common were upgraded but unity couldn't because of some dependencies on the 5.4.0+bzr2065)
- logged out/in and it works now :-/

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

i can reproduce this.

Confirmed after upgrade to unity 5.6

I ran "unity --reset" and set auto-hide in 'appearance/behavior' then the launcher doesn't reveal with the trackpad, the sensitivity doesn't change the behavior.

I'm using libxfixes 1:5.0-4ubuntu2

This bug was fixed in the package unity - 5.6.0-0ubuntu2

---------------
unity (5.6.0-0ubuntu2) precise; urgency=low

* debian/patches/01_remove_ungrab_workaround.patch:
- remove a workaround which makes alt + keys not passing events to other
apps (LP: #953783)
* debian/control:
- add libxfixes build-dep (versionned as there is an ABI break). No cmake
file was listing it, will fix that upstream as well. ubuntu4 of libxfixes
need an unity rebuild to avoid not being able to trigger launcher reveal
(LP: #953778)
-- Didier Roche <email address hidden> 2012年3月13日 12:35:47 +0100