Forced scroll bars in FF

Find switching between IE and FF annoying? Does the site jump sideways all the time? This is because IE will ALWAYS reduce the window size and display the scroll bar, even if it is not used. FF wont display it unless it is required (as it should be).
OK, this is the ‘wrong way solution’, but it solves the problem. Force the scrollbar in FF.

html { height: 100%; margin-bottom: 1px; }