condensation

[steve]

I agree with Rod...you have to get more air flow between the roofs and make sure the original venting is not blocked. You basically have 2 vapor barriers and that is your problem.
The dew point (where cold meets hot) is supposed to be on the outside of the roof insulation so adding insulation on top of the old roof may help but at this point I think your only solution is to get more active (fan) air flow