Comment 10 for bug 591129

Hey,
I recently discovered this problem too. It's probably a problem related to PolicyKit, indeed, and we can verify this very simply : the problem is solved by starting the software-center in the shell, via "sudo software-center".

I wanted to add two things to the discution :
1/ the solution proposed by quarkrad doesn't work on my computer ;
2/ the problem can be extended to all the other applications which require a call to PolicyKit Authentication Agent. For example, on my computer, I have exactly the same problem in the screen System > Administration > Users & Groups. None of the buttons work properly, for example "Advanced parameters" or "Add [a user]".