There are 4 basic methods of moving keyframes (2 methods involving multiple keyframes on the same layer): Click, Shift-Click, Ctrl + Click, and Alt + Click.
There are variations depending on whether usage is within the Slide Options or Keyframe Editor. Photodex never got around to documenting these methods, as far as I can tell. That is, I've never found this information anywhere in any of their documentation (so, I guess all of these methods are still "secret"). The link below, however, is to a post that provides information on what I've discovered over the years:
viewtopic.php?f=24&t=23123Dale