We just moved into our new home 5 months ago. about two months ago we began having a musty smell in the courner of one of our bedrooms. we have had mold companies out to test and have done several holes in the sheet rock to find the smeel but have been unsuccessful in locating it. we have now focused on the outside brick. we removed a few brick and have had the smell somewhat for limited periods. the smell is only present usually in the afternoons and is gone in the morning. it is also usually on overcast days not warm sunny days. does anyone have an idea where it might be coming from or the cause

When the mold test companies came out, What kind of tests did they do?
Is there any heating vent near this smell?

Mildew smells are caused by the outgassing of materials that are damaged by moisture as they decay. Just like the dish rag in the kitchen sink that sits there for a few days.

When the bricks were removed, did anyone do any moisture tests on the exposed sheathing of the home? What about the floor, walls on the inside? You need moisture to get smells from mold. No moisture no mold.

Sometimes the insulation used in homes gets damp from leaks. When this happens the stuff can get real stinky. What if anything have you done to rule this material out?

What way is the house facing? Does it get lots of sun on that side? Being in Tulsa, what about below the room, is it a crawl space, slab or basement or is this in a second floor room?

Also some plastics and materials can give off odors that mimic mold. Plastic runners, wall paper, drapes a whole host of things. What is diffrent in that room then the others?

If you can get your hands on a black light. Use it in the evening with the other lights off. Any lit up areas from the light, other then the old shirt your wearing? Many molds and fungi will glow in the light. Also so does animal stains. May help pin point something overlooked.

Just in,
I read today about the use of Chinese Drywall. While I do not know about your area, but many homes that were built the past few years used materials imported from China, It appears that the chemical makeup of the material was such that it causes as quoted by MSNBC press "The drywall apparently causes a chemical reaction that gives off a rotten-egg stench, which grows worse with heat and humidity"
Complaints are walls emitting smelly sulfer compounds that are getting familys sick.
Google Chinese Drywall Complaints for complete information on this subject.