Both of my steel entry doors leak at the 90 degree point where the frame and threshold meet. The water seems to seep through the corners. I've tried caulking them from the outside, but they still leak. I talked to Lowe's about it, and they said to check the pads at the bottom, which are stapled to the frame. They are fine and seem to be in the right place. I'm not sure what to do to stop the leaking. Please offer your suggestions if you may have some.