Grind & Brew 12 cup coffee maker- Model #DGB500BK - Serial # 51228C

Our 3 year warranty will be up in March 2009. The coffee pot brews half way, stops and then if we turn it off and start it again, it will sometimes will finish brewing - Somestimes it will not, and the coffee is not ward. We tried decalcyiiing with vineger twice - however it then works once and goes back to the same routine. We didn't see anything else in our manual that we could do to rectify this. Can you makeother suggestions?

Thank you for your prompt attention to this matter.