I discovered today that my Lee Filters 77mm adapter ring will not screw onto my Canon 24mm f/1.4. Neither will my 77mm B&W circular polarizer. Both work fine on my 24-105 and 70-200 and thread in quickly and easily. Has anyone else had this issue with the 24mm? I guess I need to send it in to Canon because I sure don't want to force something that could lead to greater problems. The lens is still under warranty and it's never been dropped.