would this work as well??
..
create a skybox w/ mountain terrain but w/ no sky (instead apply a color used for masking/alpha) and then create a skybox/sphere behind that that you could then rotate.
that way you could have a nice rotating sky, but w/out ur mountains rotating as well.
i'd try this out myself right now, but i'm at work.. it'll have to wait til i get home.
..
create a skybox w/ mountain terrain but w/ no sky (instead apply a color used for masking/alpha) and then create a skybox/sphere behind that that you could then rotate.
that way you could have a nice rotating sky, but w/out ur mountains rotating as well.
i'd try this out myself right now, but i'm at work.. it'll have to wait til i get home.