We have a small gap on the hinge side of one of our windows. when you close the window, just as the handle side meets the frame there is a small click and the bottom hinge side "jumps". As a result you can actual see a small amount of daylight between the fixed frame and the opening part. the windows are about 8 years old. This problem happened soon after installation and the supplier fixed it, but they're out of business now. Any ideas