We installed about 40 Kolbe Ultra Clad Windows in 2003. We have since discovered that the windows sashes (both fixed and active) are rotting away. The problem appears to be in the lack of angle in the sill. The sill has an almost non-existent angle which allows water to stand on the sill. It is subsequently wicked up into the aluminum clad sash and rots the sash. The distributor (North American Windows & Doors in West Chester, PA) came to investigate and determined the windows were installed correctly and agreed to replace about half of the sashes. This however only covers half the problem as all but 4 of the windows are rotting. It also is only a temporary fix since the sill appears to be the issue. The problem will not be resolved unless the entire window is replaced. I contacted Kolbe directly to say I dispute North American's assessment and would they please have a rep come out but they told me they stand behind their distributor. We are talking about $40,000 worth of windows plus installation. I am getting nowhere fast with Kolbe or their distributor and don't know what to do. Evidently I am not the only one with this problem as I have found numerous complaints on home improvement blogs. I wish there was a class action lawsuit to get involved in so I can get some money back and replace these windows with something better by a company that stands behind their product. Whatever you do, do NOT buy Kolbe & Kolbe products, You will be sorry.