My Bosch Dishwasher doesn't clean

However carefully I clean the filters, stack the contents, use high quality dishwasher tabs etc the machine leaves food debris all over the plates and inside the machine casing. Any stray rice grains or spinach causes particular problems. I can't work out how the food debris can actually pass through the filters and be pumped out. I am clearing the plates so thoroughly now that I might as well wash them by hand! I have never had this with other makes of dishwasher that I have had before. This was an expensive machine, it is only a few months old and I am thoroughly fed up with it. Like Chiggsy I clean the filter very carefully but food is often left on items; also, clean dry cups and glasses foam a bit when water is poured in as if a soapy film has been left. When I rinse carefully subsequent fillings are OK. Previous dishwashers have had a fine gauze filter fitted to the outside of the courser main filter. In my current model this fine gauze fits below the perforated "tray" in which the main filter fits and relies on compression (as the main filter is screwed down) to seal it top and bottom. as the main filter only screws down so far (bayonet fitting) I am not sure how well the fine one seals. Model is Exxcel (can't find more detailed reference) The top rack cleans fine....the bottom rack doesn't...As odd as it seems the left front bottom doesn't clean well..I don't see a blockage and the arm spins freely...HELP!!