Amana ADB2500AW 24 in. Built-in Dishwasher

This dishwasher has not had one completely clean load. I have owned it since September 2006 and have had 4 different repair men here to look at it. Every load there are food particals left on the inside of glasses that weren't there before the wash. Sometimes it is left on plates and bowls as well. The silverware always has food stuck to the bottom of it where it sits in the basket. I do rinse the large food remains off before placing in dishwasher. I run the hot water before starting, I use less soap and shake the soap before using (as suggested by the repair guys). I think it is loud and does take a long time. I use the heavy wash for the best clean, but still unhappy with the performance. I bought this dishwasher for the price and because I bought a refrigerator from Amana. The drying works well and I do like some of the features.