Thanks for the followup Chris. You probably will want to replace the wet insulation sometime so get out the plastic when you do it. As the insulator indicated, to keep the moisture out of the attic, you have to stop it from coming in from the living space. As I mentioned in my post, we build houses like a chimney with all this special wall materials, double pane, low e windows and doors, etc. and then we build ceilings like we did 50 years ago by nailing/screwing drywall to the ceiling joists and laying insulation on top. Go figure. You can buy a high priced convertible and still end up with a rag top car, for example.
Unfortunately, people, furnaces, fireplaces, bathrooms, basements by way of ground moisture, etc. all produce moisture and it has to go somewhere. It is near impossible to achieve a perfect seal off of moisture from going through the ceiling going into the attic just like we can't achieve a perfect seal off of moisture in basement walls and floors. Sealing off the ceiling and walls completely will just trap moisture in the living space and cause all the mold and mildew and health problems(we've had lots of posts on that stuff) we have to deal with.
In this day and age, there is not going to be one quick fix. I suggested a number of problems and possible solutions and it is still going to take a combination of things to fix the problems. What you do is your decision.
For an example of perfectly sealed up walls and ceiling, make you a tent in your living room with some plastic, get inside, and leave a place in the bottom open for breathing air. Before long the moisture from your breath will fog it up and it will be unbearable to stay in. For another example of how much moisture we exhale, just go outside on a cold and dry day and look at yours and everyone's breath. Watch the breathing at a football game in Buffalo, and it don't take long to realize the moisture from breath alone. (now add the furnace, fireplace, gas water heater, etc.) I think that will help you understand how ventilation and dehumidification are still important parts of maintaining our living environment. (think of the icicles hanging from your bathroom vents as "bathroom breath", lol)
As I hark back to younger days, I think I was probably more comfortable living in those older and less tight houses that were built before we had the energy crisis.
Good luck Chris. When and if you come up with a fix for your moisture problem, post back with a new post to let everyone know how it went. This board is also to educate the public and all help and experiences are appreciated.