First thing to check is both tuners are working (assuming you have two cables connected).
When you did the reset did you get a two tuners found message ?
If only one post for a different check for two tuner operation.
Try this with nothing set to record.
Tap in 105 to display Channel 5 HD – press the red recording button.
Tap in 102 to display BBC 2 HD – Does the programme show ?
If so press record again to start a second recording.
tap in the following channel numbers and confirm that all of the following can be watched while both recordings are ongoing.
128 Channel 5 +1
129 5 USA
130 5 USA +1
131 5STAR
132 5STAR+1
133 My5
141 Spike
972 BBC One HD England
978 BBC One NI HD