Here's a link which(especially for Dominic re.the above post)should make fascinating reading for any diver.The extended treatment,in this case a week is self explanatory.The more technical details however are not and one can only presume that as "bubbles"are responsible for the signs and symptoms it must be that in some cases they don't shift without extended treatment.
http://www.photo.net/travel/diving/d...ession-illness
(Edited by Hobby at 1:19 pm on Nov. 4, 2002)