How to bring the clock back to the center in gnome-shell?

I am using Gnome-shell on Ubuntu 11.10.

For some reason, after I added the usual extensions (Weather Indicator, System Monitor etc) the clock moved to the right - I did not install an extension for it to do so; it just did.

How can I get the clock back to the center?


(converted OP answer originally in his/her question)

The solution I found to this is as follows.

  1. Click the system monitor,
  2. go to preferences and
  3. untick 'move the clock'.

Another extension that causes this behaviour is "Extend Left Box" -- I had so many extensions that I didn't notice it, and then I installed "Status Area Horizontal Spacing" and had to poke around a bit.