What should I do if the Portafilter comes off during the espresso pour?

Ensure that all three tabs of the Portafilter are fully inserted into the Group Head and rotated to the center position. If the grounds are too fine, change to a coarser grind, or if tamped too hard, tamp the grounds more lightly. Also ensure the top edge of the filter basket is free of coffee grounds by cleaning around the edges and wiping the group head clean. If the group head rubber seal is damaged or worn, contact Calphalon Customer Care. (Page 23)