I have the same problem and has been trying to do more range of motion that I have been doing, going all the way up and all the way down locking out the elbow in pull-ups and locking out the elbow and squeezing the triceps on bench curls. The only part of my arms that feels sore the next day now is the part I want to make bigger. So far the biceps look a little better but far from perfect.
This is an old thread, have any of you guys seen any improvements from changes to your workout?