check to make sure the hinges are screwed in tight. then open the doors and check one at a time in the closed position to make sure they are plumb. make sure the base is level with support along the entire bottom of the door. Recheck plumb and level, not just against the frame but at the hinges as well. Measure the top and the bottom of the frame.
When screwing the frame to the wall framing make sure the shims are in tight, if it sucks in when you tighten down on the screw that will throw all the plumb out of whack. If your doors are uneven something is not plumb somewhere. If the doors are sticking/dragging/rubbing the top make sure it is level all the way across the opening it may have a bow at the top in which case you would need to shim it to the correct position and drive a screw there.
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