The only problem I've had was that when I got back from lunch yesterday I had to change back from the default colour scheme which had activated itself to the one I normally use (SMF default?). Other than that, no problems (which says a lot considering how badly the forum runs on my pc here at work).
In the process of typing this post the skin changed again and when I went to look all the other forum skins have been removed. Does leaving a choice cause problems with the forum software?