The musty smell is probably the odor given off by the mold and mildew. Even though you're done what you did, there may still be moisture down there. And if this is the case, it's probably getting into the other living spaces in your home too.
You can take a sheet of plastic (or a large plastic bag) and lay it out in about a 2' by 2' area on the basement floor, then tape all the sides down with, say, duct tape. IN a couple of days, rip up the plastic and see how much condensation is on the bottom side of the plastic. This will give you an indication of where the moisture is coming from. YOu can tape the 'same' to the walls too. (In BOTH cases, I'm assuming you have a concrete or tile floor. If you have carpeting or otherwise, find a spot where you can tape the plastic as directly as possible to the floor.)
Circulation of air down there would help too. If you hang your laundry to dry out down there, leave a light on to help dry out the air. Hopefully, your dryer vents to the outside; not into the basement or an adjoining crawlspace. If you have a dirt crawlspace, you should cover it with 6 mil thick plastic and put bricks or timbers along the border to hold it down.
If you need more, post up. My best to ya and hope this helps.