Flashing delicate (50degree) light flashing?

I'm having a problem with my dishwasher and the delicate wash cycle light flashes. I set the dishwasher up on a cycle (normally intensive) and set it going. Everything seems to be fine and then suddenly during the wash cycle everything stops and the light flashes. At this point I can do nothing with the machine until I have turned it off at the mains for several minutes and then turned it back on again. Anyone got any ideas as to what the problem may be and if we can fix it ourselves?