Comment 40 for bug 720960

i experienced this error after removing unity software from my system...
but was able to fix it by following one of the above stated workarounds:

        jtlb wrote on 2011-04-15: #8
        this bug occurs in the function "UnityLauncherAutoHide" of file "/usr/lib/python2.7/dist-packages/ubuntutweak/modules/compiz.py" which is called from line 351.

        if you do not require this specific feature, you can replace the code line 350 to 351

        if system.CODENAME == 'natty':
            self.launcher_autohide = None
        else:
            self.launcher_autohide = None

     by this single line:
          self.launcher_autohide = None

->the only difference i saw was that this code occured on line 353 for me; copy and paste above code, and restart Ubuntu-Tweak