I just installed Mythbuntu and my hardware seems to be working OK (hauppauge wintv 878/9 in a Cisnet box). I can watch TV using xawtv but not in MythTV. When I fire up MythTV I get the following error:
mythtv is already using all available inputs for the channel you selected, if you want to watch an in-progress recording select one from the playback menu. If you want to watch livetv cancel one of the in-progress recordings from the delete menu.
I'll post up some screen shots of my MythTV config when I get home.