Non of you has said weather the condensation was in between the panes of glass or on the inside of the house on the surface of the glass. Nobody has stated what the outside temperature, inside temp was when the condensation formed. Is anybody using a humidifyer? As a general rule the lower the outside temp the lower your R.H. should be set inside. I don't care what brand of windows you own when warm moist air hits a cold surface you will get condensation. I know your going to say that the double pane windows are suposed to eliminate this. Well it does up to a point. When the temp outside gets down into the teens or below the glass on your windows are going to feel cold double panes or not. Dropping the humidity level in your home will keep moisture from forming simply because there is not as much in the air. As for American Craftsman windows I must say I have had no problems with them and have only good things to say about them.