A. Actually, I did eventually have this problem with my very first humidor, a 25-count box made by a very high-end company. The lid would just slam shut. But at the time I bought it, I didn't know what to look for in a good humidor, and bought it solely on name alone. I still have it, but keep it in the FSS warehouse humidor with my private stash, so now the leak is negligible.

I have two solutions for you: One, take the humidor to a professional woodcrafter and have him place new Spanish cedar pieces in the lid portion of the humidor. This apparently gives the box a better seal. If the walls where your box seals come up from the bottom of the box, it might be easier to replace those instead. Get an expert's opinion.

You can also try using some very thin weather-stripping material, but unless you get it in there just right so the lid closes properly, it may not help, but it's worth a shot. If the box is worth repairing, better to go with the first solution.