I had this problem as well with the ram I just bought, Only thing is I know my drivers side latch is busted, but my passenger side wouldnt open. So I soaked down the latches with pb blaster and let is sit for a few minutes. After that I got in the back of the truck with the seat up and gave it a couple of hip checks while holding the latch...The door didnt stand a chance.
The latch basically rusted itself on to the latch.
Now just to fix the drivers door.