This is weird. Sounds like it could be a few things. I would start with ensuring that the bearings on the cutterhead are not worn out. Do this by grasping the cutterhead with the power disconnected and try to wiggle to see if there is slop-There should be NONE. Also, while there, ensure the blades are not loose. The next thing is to ensure that the blades are sharp. If not, they could be causing large tearout (Hence, the pop)which could lead to the board popping upwards and sniping. The last thing to check would be that the infeed/outfeed pressure rollers are doing there job to hold down the board. Good luck!