Can't run bleachbit as root by clicking the menu icon on Ubuntu 13.04

[Ｖ字龍(Vdragon)]

Reproduce steps
-------------------------------
A.
    1. Find "Bleachbit (as root)" from Unity Dash and click on it.
    2. Enter your password on gksu's prompt

B.
    1. run 'gksu bleachbit' from Alt-F2

Expected result
-------------------------------
* Bleachbit runs normally

Result instead
--------------------------------
* If LANG set to zh_TW
    * An error window pops up as the screenshot in the attachment(I added translation)
* If LANG set to en_US
    * It indicates that the password is wrong even you sure you typed in correctly

Other information
--------------------------------
* I quite sure this won't happen in Ubuntu 12.10
* Probably is gksu's issue instead

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: bleachbit 0.9.3-1
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic i686
ApportVersion: 2.9.2-0ubuntu8
Architecture: i386
Date: Thu Apr 25 23:21:06 2013
InstallationDate: Installed on 2013-04-25 (0 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: bleachbit
UpgradeStatus: No upgrade log present (probably fresh install)

[Ｖ字龍(Vdragon) (vdragon)]

Screenshot when LANG=zh_TW

[jake (jake7264)]

Ubuntu 13.04
1/ install "Main Menu" using Ubuntu Software Center
2/ open Main Menu (applications/system tools/preferences/main menu)
3/ go to system tools (in Main Menu) and find Bleachbit (as root)
4/ double click Bleachbit (as root)
5/ in Launcher Properties change existing "Command" to:
gksudo bleachbit
6/ close Launcher Properties and MainMenu
The beast should behave correctly from now on

[Launchpad Janitor (janitor)]

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