This problem has obviously been fixed given that this was over a year ago, but if anyone else has the same problem in the future... it's the heating element at the bottom of the dishwasher. Everytime it kicked in to heat up the water it tripped my main fuse. The element was no longer a consistant colour all over and had a dark patch on it where it was overheating.
I replaced it and it's as good as new.
Brendan, April 2011
