Pop-Over Challenged!!

I'm popover challenged!! I can't for the life of me get this right!! I bought the "popover pan", read the directions carefully.. and even followed them.. with only a tiny bit of luck.. See these popovers are suppose to puff up like crazy... mine only puff slightly like a muffin top.. not a huge top!! Any ideas????? And yes.. .I pre-heat the pan and pour in the batter.. even turned up my oven temp..??? I'm out of ideas...