Media Center Trouble - Gone!
Sometimes things aren't as difficult as they seem...
After some extra reading, and searching on gathering.tweakers.net, I found that everything I had done was correct. The only uncertainty was my graphics card. I went out and bought me a faster one (a Radeon 9550) and everything works well! As I am typing this, the same machine is playing a sweet K's Choice song and recording a TV show, while displaying media center on my TV without any problems. Me likey.
I'm glad I got this thing to work within my holiday. I don't wanna think what could have happened if it didn't work and I had to go back to work again... ;)