I had problems trying to one hand it when opening, as the latch would seem to catch. Then I didn't get it fastened one day and I lost the little slotted rubber piece and I also cleaned the slot out where the catch goes, real good. I don't know if it had some sticky stuff in it , or if not having the rubber piece makes the difference, but now, when I unlock it, the latch falls away every time.
Also, a word to the wise....2 years ago, I put a partial left over bowl , with cellophane cover, of my wife's famous Italian Salad in the top box to come home from a church potluck. It of course turned over and leaked some juice out. I have scrubbed, Fabreezed it, Lysoled it, rescrubbed, left open to air out , put a box of baking soda in it, and two years later, every time I open it, I still get a whiff of that spicy salad.