Cannot install apps on new Jsilbreak 0.6.9

I have successfully jailbroken my ATV2 several times. Due to a powercut, I had to jailbreak again using the latest software. All went well and I got to the maintenance menu. However, when I go to install Plex etc, nothing happens. It says it is installing but screen goes blank and nothing has installed. I HAVE managed to install Last.fm but that's all. Any advice?

 

Can anyone give me a link to 0.6.8 as this worked foe me.

 

Thanks