Hi All.
Well Brian, your solution has worked thank you.
I rolled the box back to the 1.1.09 firmware as suggested and the greyed out menus became available. I then performed the update to 1.02.20 and the menu's greyed out again.
So I returned the box back to 1.1.09 and tried to delete the media files that could potentially be causing the problem. This worked for some files and folders but eventually the box refused to delete anymore files.
At this stage I decided to scrub the box and performed a factory reset and hard disk format.
Once up and running again I then restored the firmware to 1.2.20, reinstalled channels etc, and now all is well.
Thanks to everybody for taking the time in helping me sort this problem out, it is very much appreciated.
Al