There are some tricks to help most divers. As Bill said and my instuctor's words "equalize early and often". Another one to try, and you can discuss with your instructor is: decend in upright position looking up at the surface when you equalize. This stretches the tubes and allows the pressure to equalize easier on both sides of the ear drum. Also before the dive try some neck stretches, tilting your head side to side gently not jerking. Again it helps to try to stretch the tubes. Do note that swimming down to your depth like the pros (that is with head pointing down at the bottom and your fins pointing at the surface) positions you so that it is harder to equalize. This problem should go away with time providing you don't have a physical limitation. One more thing I'm sure you're instructor told you is when you feel the pressure don't continue downward, go up a couple of feet until you equalize. If you had a lot of ear aches as a kid you may have narrow canals and should consult a doctor about this sport. The techniques I mentioned can be practiced in a pool. Good Luck.