Our dishwasher came with the house and it's worked fine for a year. Now it seems like the rinse cycle just keeps going on and on. It eventually does stop, but I'd say hours later. (I'm not home by then.) Today I opened it during rinse to see what was going on....water was hot, spraying normally, so I just manually stopped the cycle. What could cause this or what can I troubleshoot? It's a Frigidaire model number FDB510LCB0. There is no date on it but the matching microwave (gallery series) says it was manufactured in 2004.