Apart from totallymaxed last post, which I 100% support let me add one small little tid bit of information.
Whenever someone comes into IRC and asks about how LinuxMCE does various things, and why it is not doing stuff in a specific way, I ask the person, if all they want is a media center. In my humble opinion, if all you want is a media center, there are systems and projects out there, that are more forgiving in the choice of hardware and might give you more of what you are looking for. And I am not thinking about commercial options, but lots of other free software out there. Heck, if you are in DVB-x land, you might be happy with VDR alone, as it plays DVDs, has support for USB sticks (iirc), and does TV.