Unity Tweak Tool won't Launch Ubuntu 13.04

Unity Tweak Tool won't Launch Ubuntu 13.04

I am having a problem with unity tweak tool. I use unity as my desktop
(actually laptop) interface. When I downloaded it and opened it for the
first time, it came with an error saying it crashed and needed to
relaunch, so I relaunched but to no prevail. then one forum suggested to
download the new beta version from specific repositories, but after I did
that and I tried to launch nothing happened. Then I tried it on terminal
and here is what it said
samuel@KVT-Linux:~$ sudo unity-tweak-tool
[sudo] password for samuel:
schema com.canonical.indicator.sound not installed
Traceback (most recent call last):
File "/usr/bin/unity-tweak-tool", line 72, in <module>
UnityTweakTool.Application()
File "/usr/lib/python3/dist-packages/UnityTweakTool/__init__.py", line
92, in __init__
self.run(pageid)
File "/usr/lib/python3/dist-packages/UnityTweakTool/__init__.py", line
104, in run
self.connectpages()
File "/usr/lib/python3/dist-packages/UnityTweakTool/__init__.py", line
117, in connectpages
from UnityTweakTool.section.unity import Unity
File "/usr/lib/python3/dist-packages/UnityTweakTool/section/unity.py",
line 813, in <module>
Unity.add_page(unitysettings)
File
"/usr/lib/python3/dist-packages/UnityTweakTool/section/skeletonpage.py",
line 48, in add_page
page.refresh()
File "/usr/lib/python3/dist-packages/UnityTweakTool/elements/option.py",
line 62, in refresh
self.ho.refresh()
File
"/usr/lib/python3/dist-packages/UnityTweakTool/section/spaghetti/unity.py",
line 92, in refresh
interested_players = gsettings.sound.get_strv('interested-media-players')
AttributeError: 'NoneType' object has no attribute 'get_strv'
samuel@KVT-Linux:~$
any idea how to fix this? any help would be appreciated, thanks