for some reason Windowshade X seems to really hate Omniweb. I've never managed to get the two to work well together (I'm using sneakypeek of omniweb 4.1, build 20 right now). Occasionally it manages to windowshade properly, but more often than not it just totally kills omniweb to a spinning disk icon, redraw errors, and can only be fixed by force quitting it and starting it up again.