A number of things come to mind. Are to grippers on the impression cylinder opening and closing correctly? Does the gripper shaft need oiling. What type of stock and ink are you running. If the image is too heavy plus tack of the ink might be pulling the sheet out of the grippers as it sticks to the blanket. Use tack reducer to help release off the blanket especially if you are running enamel stock. Make sure the pile is just high enough to feed only one sheet at a time. If doubling it might send the second sheet flying. With t-head blocking your view it is hard to see the feeder. Swing the t-head out of the way to get a good view of your feeder and make sure it is set up correctly for the stock you are running.
