E.A.
I have the same problem! They are just so active and into exploring things that they can't sit still for a diaper change :)
I also have found that giving him a toy to play with or something "new" to discover has helped. He enjoys finding new things so anything that he may not have seen for a while may help... I know you said you have one set aside for diaper changes, but a new "something" each time could possibly help. I know how you feel, and I wanted to say good luck to you!