Hatch won't Latch
 

I have a 2002 Montero Sport. The rear hatch door will not latch when I close it. This happened last year and shortly after I had to replace the battery. The hatch latch began working properly again with the new battery. Now it's happening again but the battery is still good. I oiled and greased the parts, so they are not rusted closed. Could it be an electrical problem or is it just coincidence that it stopped working when the battery went dead?
Thanks for your input.