Yes I resolved my mythtv problem. Although mine is not consistent with your cause. My Mythtv problem was caused by me replacing the MythTV_Plugin.so file with my own pre-compiled version (omitting some forced options like where mythtv save video files). My problem was something simple, I was compiling a 32bit version of the .so and was trying to use it on an amd64 platform, which I know does not work so I don't know why I did a bonehead that. I eventually re-installed using the i386 version since I couldn't get anything to compile for amd64.
I found my problem by watching the /var/log/pluto/DCERouter.log as the router boots up. I saw a message in there saying something to the effect of "PLugin MythTV_Plugin.so not registered wrong elfclass (ELFCLASS32).".
As you can see from the error message, I realized my mistake immediately. Maybe you should try watching that log file from another computer at a terminal as the system is booting and see if there are any errors about registered the MythTV_Plugin.so. The content of the error message may point you in the right direction.
Otherwise re-install, seems like the most common fix around here. I know i've re-install hundreds of times just to fix minor problems because there didn't seem to be any other way. I eventually set my system up so re-installing is nothing but 45 minutes to me. Copying all my save configuration, modified binaries, etc... is a 2 minute job and viola i'm done if 47 minutes.