For the last few days, when I switch my Fox T2 on and go to the channel guide, only the HD channels are shown. I have to select 'group' (blue button) then 'TV' from the drop down menu to see all channels. It looks like I have changed something, but I don't know how. I've looked in the manual, but don't see how to go back to 'TV' as the default. Can anyone help?