This is happening with increasing frequency. I don't know if it always happens when I'm coming off my mount but that's what I was doing the two times it happened tonight. I'm coming off my horse and my character starts autorunning forward and nothing can stop it. No key or mouse commands work, there is nothing I can do except run until something stops me. All I can do is force quit the game and start over. Lost out on two dragon fights tonight because of this problem and it's starting to drive me crazy.