Just a quick note that my slideshows, which were previously working ok, do not work with versions 2.1.20 and 2.1.21 (merely showing an area of little height containing the grey control bars, slightly offset, with no images or slideshow). None of the other plugins I have are clashing with Slideshow, verified by deactivation. Jquery is working fine. A rollback to 2.1.19 finally solved the issue (although annoyingly the lists of slides were lost from every slideshow declaration and had to be re-added). I use Firefox v17.0.1.