Wow, you've all made me hungry!! I'm going out to buy pork chops. Pork is the best meat to buy here in Quebec - there's a huge pork industry and there are lots of Quebec recipes for pork that are really delicious.
I find that fresh pork chops are more tender and moist. Not so after they're frozen. If the heat is too high or they're cooked too long they get hard and dry. Have you had your oven temperature check? Maybe it needs calibrating.