February 11, 2011 
Last year at TechED Berlin, I was complaining to the MDOP team that the backspace did not work in the GPMC when AGPM was installed. It transpires the issue is not with AGPM per se, but with the GPMC.
Yesterday, whilst looking through the new KB’s I discovered this one: BACKSPACE or arrow keys do not work in MMC on a computer that is running Windows 7 or Windows Server 2008 R2 (KB 2466373)
On closer inspection the article is specifically targeting the GPMC
- You have a computer that is running Windows 7 or Windows Server 2008 R2.
- You customize a Microsoft Management Console (MMC) that has the Group Policy Management Console (GPMC) snap-in.
- You select any Group Policy object (GPO), and then you click the Settings tab in the details pane.
- You select another node in the console tree, and then you use the BACKSPACE or arrow keys to perform some operations.
To resolve the issue a Hotfix is needed which is not included in Service Pack 1.
KB Article is Here.
ah ha…noticed this a couple of times and thought it had to be a bug…have not tried the hotfix yet but will give it a try.