A bit of background again, in case it's helpful. I installed the SageTV trial version that was on my Hauppauge install disk (for the old USB device that flew out during a t-storm long ago). The SageTV worked as far as providing functionality, I just really disliked their software and so searched and found NPVR. I uninstalled the SageTV software last weekend, and that was before I changed my AnalogDevice.xml file. Now that I've got the .xml set correctly I'm able to select my audio decoder, but I'm not given a choice for the video decoder, so it remains "disabled".
I downloaded the MediaPortal software and voila! I've got an encoder to select. I've done so, and now have full video!
I've got to run and do some errands, but would like to continue to build out my NPVR config when I get back. The biggest thing, I think, will be getting the TV guide to work...