If you're talking about the metal cylinder locks, make sure the inner metal lip that the latch goes behind is not bent. Ours was and we had to make some minor adjustments with a pair of pliers and a hammer (gently, and with a rag over the lip). I think that the levers sometimes don't get put in the right position and when they get turned and forced (think sales people) it bends the thin metal lip. Ours our fine now and we haven't had any more problems since we straightened the inner lip where it was bowed in.
If you're talking about the door catches for when the doors are open, sorry, no help as we haven't had any issues with those..