The issues with Media Centre and codecs is not a problem for me. I use Vista Codec Pack with 64 bit tools. The problem with Media centre I have, is caused by the Nvidia drivers which were released after 163.75. I either get smudges of black on screen with 174.xx or with 169.xx I get choppy frames going back and forth, 171.xx seems ok apart from random black screens and BSODs. I have given up on media centre and only use Media player. x64 media player is fine.
Using 163.75 and no problems with Video but cant play many of my games.