I have only had my new Keuriga K45 Elite Brewing System for 4 days, it always over flows no matter which size cup I chose. I have been using a very tall mug, and what happens is that after it starts, and it runs the cycle to fill the cup, then a few seconds later, it will start again, and will over flow, no matter how big a mug that I use..I am so very much hoping it is not broken already, as I received it as a gift, and do not have the receipt in order to return it.