APC40 unable to midi overdub?

[M for momentum]

Hi! I am sure this must be a problem easily to be resolved. I am playing around with my brand new setup of Live 8 (Mac OS X) and the APC40 and quickly discovered I'd like to do some custom mappings of my own. When I try to midi map my mappings to the APC40 I can turn any knop or press any button but none to any effect (yes, I selected something to map it to), however no new mappings are registered? The APC does have 'midi overdub' lit and works like a charm with its original mappings.

Anyone?