The problem is the default trnsponder tuned after the new EPG update, to sort it out try the following:
1. If a switch on it says no signal and 29 in the video window box then.
2. Press TV Guide Button.
3. go to the top (Functions) Bar.
4. scroll thru to Settings menu.
5. scroll down to "Picture".
6. then press 0,1,select quickly to get to service menu.
7. scoll across to TX`PONDER.
8. If it says 11.856 V as it did on mine change to 10.714 H.
9. reboot and hopefilly all is back to normal.
10.714 H is the Channel 4HD transponder and has a High signal level it seems.