just had the exact same problem. I have now found mold growing on 6 cigars including an isom which pisses me off greatly. I have brushed the mold off the smokes and moved them to another humidor and I removed the tray in the humidor that had the mold on it and cleaned it with a little bleach water and then dried it bone dry with a hair dryer.

is there anything else I can do? Did I do ok? Am I screwed like a girl on prom night?