I am installing a drop ceiling in my basement and have hit a snag right off the bat. I first installed the edge piece all the way around the wall and then put in the 12 foot long main tee. I then installed three 4 foot long tiles. I should include that my room is 12 feet wide. When I went to put the 2 foot long cross tees at either end of the center tile there were no corresponding slots in the main tee. You would think these slots would be 2 and 4 feet from the end and then every 2 and 4 feet apart over the lenght of the main tees, they are not. The closest slot in the main tee is 4 feet 3 inches from the end.