I have eventually
got my DVB-T card and my old bt848 capture card working 
.
I am in the UK and use the DVB-T card for UKTV and have the old capture card taking an analogue feed from my old D-box. (i tried to get grab to work to get digital capture, but no go
)
The pronblem /feature ?
For recording, everything works as I want it. I have the EPG's up and running, I can record Mpeg2 UKTV and analogue Sat capture.
I have a source UKTV -> Capture card DVB-T, and channels 1-13 configured. As the DVB-T card is the primary card, it is used for Live TV until it is used for recording.
I have a source SAT -> Capture card bt848, and channels 20 -50 configured. As the bt848 card is the second configured card, it is not used for Live TV until the primary is recording.
When I want to watch (LiveTV) Sattelite channels 20 + , then changing to those channels either by number or by the epg leaves the Live TV locked on the last chosen UKTV selection. I assume Myth tis trying to use the DVB card to tune to those channlels, fails and stays on the original DVB channel.
As soon as I set the DVB card to record, then the Analogue card is the Live TV card, and I can watch Sat tv.
Any way round this ? It took me a whole load of googling to find out that the cards could not be cleanly selected.