There are several issues going on within the dishwasher manufacturing industry that are the cause for breakdowns such as this clog. In the big push to make all appliances more energy efficient every brand on the market is using plastic where ever it can, including the components in the drain and wash pumps. The old metal pump parts would probably have chewed up such a small piece of plastic and ground it to bits, sending the shredded parts down the drain. The new plastic components are not nearly as durable or hardy. They are unable to shred much of anything! The EPA has also come down with very strict water usage requirements per dishwasher load. As a result of having far less water throughout the cleaning cycle, the drain hose does not have to be as large of a diameter because it is not pushing the same volume of water as older models. The plastic pump parts and smaller diameter hose create a perfect storm for a shorter life expectancy as well as a higher rate of repairs. Insignificant households items such as this small plastic disc are now causing breakdowns unheard of in less energy efficient models. It is the great trade off. Shorter life expectancy for energy efficiency!