Tim. Are the windows brown or white? The reason i ask is that brown are notorious for "bowing" due to direct sunlight, but it is not normally on the hinge side. Open the sash as far as possible and hang a plumb-bob to measure any deflection in the height. Also, on the hinges there should be lugs which engage when the window is fully closed; check to see if this is happening. If you require any further help- klplastics@graffiti.net
Kev, November 2006
