Hi Kev
This is a common problem with these boxes some times its a softwhere glitch just kill all power to it for a 12-24h period this some times solves it. if not then it is the internal harddrive that is the problem so if you know wot you are doing kill all power to it dismantel the box and remove the hard drive lead both power lead and the ide lead this solves the problem allthough this disables the recording facilatys of the unit.the hard drive is a standard computer so chould be replaced with simmerler drive and should work as normal if replaced with new drive I've not got around to putting a new drive in it yet but works fine for me as an standard freeview box without the record feacher.
Hope this is of some help to you
good luck
gav
gavin dippie
August 2009