My experience : I am PPL student, never had any serious problems with ears, but rather tend to catch cold from time to time. Have got my medical class 2 with no problems at all.
After having constant discomfort and, sometimes, pain in my left ear during descent, I took painful decision to suspend my PPL training and investigate on what is going on. On top of that, I was frustrated about getting cold three times during last three month!
After making investigation at two independent places, it appeared to be that - now, sorry for possibly incorrect terminology - my "nose separating wall (partition)" is curved and nose inner shells are increased in size. Curve of the nose partition in combination with big shells make air flow problematic. Problematic nose air flow leads to increased probability of getting cold and ear pressure equalizing problems. So, in my case it looks like physyology making troubles. Now they recommend me operation on fixing the curve and then possibly the shells.... I have not yet decided, but I hope that in case it is done I will be able to keep my medical and continue to fly. JAR-FCL 3 do not give clear information on whether it's OK to fly after such operation. Need to consult aviation medical specialist on that.
I wish you guys good luck and easy solutions for ear pressure problems....
Happy landings,
Alex