Miele G595 SC dishwasher stops on Interim Rinse?

Hi,
Now my dishwasher stops on the Interim Rinse part of the cycle. It has water in the bottom. I have cleaned an enormous amount of gunk out of the 'tubes' in the bottom of the dishwasher and run several cleaning cycles - very successfully. The inlet light is on every time it stops. It seems to stop on any cycle at this point with 0 in the display. If I turn the machine off and leave for 10 minutes then run another cycle (without any new detergent) the cycle completes successfully. Weird! We still do not have a catch for the dispenser so wonder if this is the problem - although can't actually work out the logic to this. Would like to get a catch if anyone can help there. If anyone has any ideas on why it might stop in one cycle (so far into the cycle) and then run successfully on a second run, would love to hear them. I now believe the inlet light is just a red herring.