[hugger6933]

Now this may not make sense but sometimes going all the way in with a latch can be too far. I've had loose doors that when you would move the latch or striker all the way in it would lack what seemed like a half a notch on the latch being all the way closed. Well most all latches have two positions and if you go all the way it will close like one and a half notches so that means coming out just a tad then the second notch can catch. Clear as mud, right.
One thing I have done on the back doors is place a breaker bar or long pry bar on the striker and pry [or hammer] it up. That sometimes can tighten a back[ third] door. Good luck. Jim