You say you are afraid of moisture and drywall?What type of insulation did you install?I would look there first.

There's a new interior wall product by Georgia pacific that is essentially drywall without the paper. The claim is that moisture (mold) travels along the paper of the drywall. This product is designed for basements and baths.

I'm planning to replace the bottom 4' of my drywall with this product.

http://www.gp.com/build/product.aspx?pname=DensArmor%c2%ae+Plus+Interior+Wallboard&pid=4659&hierarchy=pc

datadiva-You say you are replacing the bottom 4'?I am wondering why 4'?Point I am trying to convey here is you should look behind the drywall for moisture issues.If you have moisture present there a product that discourages mold really is not going to help you,it just traps moisture.

The little bit we did have was on the bottom few inches in a corner we didn't easily see.

The contractors ripped off the bottom foot or so and checked the insulation behind it for us (This is not what we were hiring them for) and we had cought it before it got that far.
They have ripped out the bottom two feet for me but at the time we thought the sheets were in 4' dimensions.

We got the carpeting removed, and we're waiting to make sure the landscaping fix holds before we re-do the floors and walls.