Turns out the MythTV failure was due to missing the OSS digital data interface in the Alsa module of the kernel (PCM), Myth was crashing in the middle of trying to work with the /dev/dsp interface without it. The card has again changed it's colour settings, but no big deal there.

Only major fallout still in place from the swapping of kernels is that I still have the system clock running fast (on the order of a couple of minutes/hour, with reboots seeming to trigger some substantial changes (on the order of 20 or 30 minute jumps)).