[launcher][precise] Tooltip flicker when mouse is over the "current window" triangle

[Roman Yepishev]

Steps to reproduce:

1. Start Unity 2D
2. Open some application from the launcher
3. A "running" triangle appears at the left and "current window" triangle on the right.
4. Move mouse over the right triangle

Expected results:
Tooltip appears

Actual results:
Tooltip appears and disappears at a very high rate.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity-2d 5.10.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic-pae 3.2.14
Uname: Linux 3.2.0-23-generic-pae i686
ApportVersion: 2.0.1-0ubuntu4
Architecture: i386
Date: Tue Apr 17 01:13:05 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20120313)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity-2d
UpgradeStatus: No upgrade log present (probably fresh install)