After sorting out all the RPM dependencies for MythTV In finally managed to get the it installed on my media center. No I didn't use LinuxMCE, I just installed all the RPMs using yum. Unfortunately I couldn't get any audio or video out of it. This was purely a configuration issue but I didn't know it at the time. Instead I jumped into wrong conclusions when I read a couple of posts that said MythTv 0.20 isn't compatible with the Asus MyCinema P7131.
That conclusion isn't all that wrong either. MythTV 0.20 really doesn't work with it, but 0.20.2 is compatible. And that is exactly what was installed on my machine. So like the fool I am, I removed it with the greatest difficulty (yum again complained about dependencies when it shouldn't have done) and installed MythTV 0.21. That version hasn't yet been released and it's only available through the 'bleeding' version of the Atrpms repository.
After installation of this version (but not because of it), I am finally getting some video on my screen. Unfortunately there is nothing on the speakers.