"Open with" bar breaks the extra pane with

Description:
When you insert a media that can be handled using a specific app, Nautilus shows a bar with an "Open with" button, on were it suggest a proper app.
If you have the extra pane active (F3), this bar forces the pane to expand, narrowing the other one.

Test case:
Insert a media containing, for example, music (if asked for an app, just close the window).
Open Nautilus
Create another pane using F3.
Select the inserted media.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: nautilus 1:3.4.2-0ubuntu5
ProcVersionSignature: Ubuntu 3.2.0-34.53-generic-pae 3.2.33
Uname: Linux 3.2.0-34-generic-pae i686
NonfreeKernelModules: wl
ApportVersion: 2.0.1-0ubuntu15
Architecture: i386
CheckboxSubmission: 1c569236429244c2837ef2720aaa3765
CheckboxSystem: b845c366ea09c60efa3a45c1b5b21525
Date: Sun Nov 25 14:11:58 2012
GsettingsChanges:
 org.gnome.nautilus.window-state geometry '767x838+831+33'
 org.gnome.nautilus.window-state maximized true
 org.gnome.nautilus.window-state sidebar-width 204
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: nautilus
UpgradeStatus: No upgrade log present (probably fresh install)