btw, if your running in steam, oyu need to get pakscape (gcfscape?) and manually put in the new models and sprites. dont worry, it sounds alot worse than it is. just open up your pak1.pak and copy the models from there into your models folder. then do the same for sounds and sprites.
btw, DO NOT JUST OVERWRITE THE OLD FOLDERS WITH THE NEW ONES!! you have alot of models, sounds and sprites from the old pak still used in there!