Why can not I move / rename this page?

Revision as of 30 January 2015 at 20:33.
The [/w/index.php?title=Talk:Extraordinary_General_Assembly_November_2009&offset=20150130203400&lqt_mustshow=35 highlighted comment] was created in this revision.

I'd like to rename it to General Assembly instead of AG and it's not working for me. I could do that for the 2011 page though. Only visible difference at the moment is that this one is categorized and the other was not.