I downloaded and installed the appropriate ivtv driver for the kernel version of Kubuntu - though this might not have been necessary, but I don't want to experiment again
I looked at doing the firmware but ivtvdriver.org said to get it from hauppauge and hauppauge said get it from ivtvdriver.org...
Then basically I ran the backend MythTV setup. Myth somehow knew about the PVR 350 and I just had to make a couple of changes, add my datadirect programming account info, etc...
I checked and these two entries aren't shown in the LinuxMCE setup wizard.
One thing I am noticing is that even though I've commented out any reference to the eth0:0 net interface MythTV still picks up the 192.168.1.80 IP which causes a connection problem to the backend... I can get around this by running the MythtV backend setup, but this is a pain.
However, I am happy that it's running - the eth0:0 is something I can track down