I know, I do too, but every single time I install the add-on pack, it causes my game to crash. And it's been discussed that you need A LOT of RAM/high end CPU for it to possibly work, and considering I have a really good quad core CPU, 4gb RAM, and a 1gb ATI 4870 card and I can never get the game to be stable w/ the add-on pack installed, there's obviously something wrong there.
Good luck, but I really don't have anything for you. Every time I try w/ the add-on pack, the game crashes. When I play w/o it, it seems to work fine.