Hi JJ
I can't solve the whole problem but have part of the answer.  i have the same issue & its not a blockage as such.  The problem is with the float thing that activates the pump - this is in the little dome just by the silver grill, next to the cleaning arm.  If you lift this dome the machine will empty.  I have 'wiggled' it about and seems to be ok, could be it just got stuck.  Anyway give it a go, if you get a better answer please let me know.  Thanks
                
 laith@onetel.com
                
 March 2007