Leaks or condensation from a new metal roof?

We recently had a 29 gauge high rib metal roof installed on our 16 X 76' 1981 Gallatin mobile home in Roundup, Montana. The old shingle roof was removed and our contractor put down 30# felt under the new metal. He put in a ridge vent. There are a total of 6 existing soffit vents, 3 per side, and two eave vents at each end of our home. The roof has a 3/12 pitch and there is 6 inches of insulation in the walls and ceiling. Since the new roof has been up we have developed multiple wet drip spots in the ceilings of our mobile home, randomly throughout, but perhaps more in the ceilings that are closer to the soffit vents. There are also wet areas in the ceiling areas where the roof and inside wall come together. Since we moved into this home in March 2005, we have replaced all of the windows and have made the home much tighter. Our contractor and my husband have tightehed all of the screws on the roof and checked to see if there are any obvious problems but we can't identify anything. Our contractor does not know what to do to solve the problem, nor can we identify the cause. We don't know whether this is leaking or condensation but the roof doesn't appear to leak when it rains, only when we have snow cover or heavy frost with outside cold temperatures and melting. Do you have any suggestions as to what is causing these problems and what we can do to fix them? Any help would be greatly appreciated. Also, if we can't figure this out and fix it, can you recommend a metal roofing specialist in our area (close to Billings, MT) that we could hire to evaluate and recommend a solution. Thanks very much. Diana and Ed Tyler

I am assuming the roof deck was left in place. Right off hand, I would examine the ridge vent closely for leaks or snow / ice back-up. I would increase the number of soffit vents, make sure they are not blocked. Also, make sure the ridge vent is not blocked. And remove or cover what I think must be gable vents that you described as eave vents. Gable vents would be pulling air from the soffit vents instead of allowing air to travel in the soffits, along the bottom of the roof deck, and out the exhaust. Also, make sure that all moisture sources such as dryer vent, exhaust fans, plumbing vents, are exhausted to the outside. Avoid any undue moisture sources inside the home such as gas stoves (especially ventless ones), bathrooms without exhaust fans, larges numbers of house plants, etc.