When scrolling the mouse wheel in the gnome-volume-control for increasing system volume, It only decreases the volume

Binary package hint: gnome-media

When I scroll the mouse wheel on the 'Sound Menu', volume increases and decreases as expected; But when I do the same from the gnome-volume-control , volume only decreases even if I am scrolling the mouse up.
So, the volume only decreases whether I scroll up or scroll down (In gnome-volume-control).

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gnome-media 2.32.0-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-5.32-generic 2.6.38-rc6
Uname: Linux 2.6.38-5-generic i686
Architecture: i386
Date: Fri Feb 25 17:16:12 2011
ExecutablePath: /usr/bin/gnome-volume-control
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110216)
ProcEnviron:
 SHELL=/bin/bash
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
SourcePackage: gnome-media