I see this topic has been going for years lol. Just to agree with Matt - I had these residue problems years ago, and like people here, searched the net without a solution (if you'll pardon the pun). Eventually I told my ex about it and she asked if I had used Dishwasher Cleaner. I said No, is there such a thing?

Anyhoo, I went to Tesco (I'm in UK), and found small plastic bottles of dishwasher cleaner right beside the detergent. As Matt says, you put them upside down in the cutlery thingy, and run a cycle. For me it took 2 cycles, but then my cutlery and glasses were finally sparkling clean again - result.