I'm afraid that all I can say is "people, welcome to the unpatched version of a Bethesda game". I love their games and their releases, but Bethesda's games fail on a lot of technical aspects, most of which they never end up fixing, which is felt badly upon a brand new release, until the magic team comes up with the unofficial patch.
EDIT: this post, of course, only stands if you're playing SEE, if you're playing the old game all I can say is: get the damn unofficial patch.