It's been mentioned on this list before but I think the procedure for installing the K-cup is very important. For various reasons K-cups often have pressure built up inside. When the top of the K-cup is pierced, when lowering the lid, the pressure blows unbrewed coffee into the upper needles which can cause a clog. I think it's better to first use your two thumbs to press the K-cup firmly down into the cavity which pierces the bottom and relieves the pressure . That way coffee grounds won't blow up into the upper needles when the head is lowered. As always, good luck and your mileage may vary.