In all honesty, unless somewhere else has a miracle fix, I have run into those identical problems. They only happened when I tried to upgrade my bt-tv based tv tuner with a better PVR-150 MCE. Also I when I tried changing out the sound card. The sad truth is, during the installation process, lmce detects and installs appropiate drivers for your current hardware, ignoring everything else. You basically have the same two options I had.
1. Wrestle, fight, and research how to get the proper kernel modules loaded, change all the assoicated configuration files manually to reflect your new hardware, then somewhere coax the LMCE interface into using the new equipment.
2. Use the DVD installer and just re-install(30mins on my piece of crap slow computer) and breath a huge hmm of relief.
Suffice to say, when I added new hardware after the installation, I experienced some un-preditictable results. It took me over 20 plus installs on the same machine to get it the way I wanted it.
Trust me, life is easier if you just re-install. It's probably too late, but I didn't bother adding anything important to my installations until I fully tested all the features I wanted to work, because I knew I would end up re-installing again if I found something that didn't work quite right.