I have had the same problem and after doing a bit of surfing on the net I have managed to resolve my problem. What I found was that there were bits of left over food and bits of selafane that were blocking the waste/drainage hole (the hole to the right of where you put the salt into) the filter, so ended up scooping out all the crap from it and its done the trick. I think what happens is that because there is no way of drainage with this hole being blocked and at the beginning of the cycle it starts chucking out water, there must be some kind of sensor that indicates overflow & stops the cycle.
Ive also attached a link for the user manual if u've thrown yours away like we did.
Hope this is of some help.
http://imagebank.indesitcompany.co.uk/brochures_online/pdf/Hotpoint/Dishwashers/FDW80_85_after_Feb05_19504426705.pdf
Darren
May 2010