Your question seemed as if it was what can you the communer do to improve your effectiveness, not what goes into someone eles's ability to make their saving throw.

Several factors are in play there, one of which is level difference. Since you have specifically mentioned elves and curse, this is probably a big part of what you are seeing going on - http://forums.carrionfields.com/dc/dcboard.php?az=show_mesg&forum=3&topic_id=455&mesg_id=455&listing_type=search