A leaking tonnue cover???

I have a 2001 ford explorer sport trac. I recently bought a used ford factory tonnue cover online. The kind that is a hard top hinged in the center and locks. When I put it on and tested to see if it was waterporrf warter started comming in at the center hinge. It looks like its comming in on the center on both sides. Any Idea how to fix this problem?

Pete D.
June 2009