Mold formed on wood decor?

[Mystictrust]

Mac's Pet Refuge - Habitat Décor - Reptile - PetSmart
Is mold supposed to form on these? I don't understand. Average humidity in my enclosure is probably somewhere around 75%. There is about a one inch section of mold on either side of the openly cut section of the wood (entrance) and a ton of mold on the top underside.

Should I return and get another one that's been treated better, stick with the same and scrub off mold weekly, or get a different product? I'm just really not sure if this is normal. I have Mac's driftwood in there as well and it is perfectly fine.

[croaker]

i'm pretty sure it's a normal thing when you have certain kinds of wood in moist environments. i know for sure the the pieces of grape vine sold at petsmart mold. you could just clean it off i really dont think it would harm anything. i was happy when a branch in one of my tanks start growing small mushrooms.