The type of paint that you use on the walls of your listening room CAN make a difference (albeit a small one) in the sound. The higher the gloss level, the more tightly packed the molecules are, and the more reflective the surface. Ideally. you would want the most porous paint that you can find and this would be flat, non-acrylic, clay based crap. Most paints that are marketed as "maintenance grade" (Conco, Old Quaker, anything around $10.00 a gallon) would fit the bill. Also, most products that are sold as ceiling paint would fit into this catagory.
The down side is that these paints are not at all washable, so if you have small children, large animals or frequent food fights, you might want to consider biting the bullet and purchasing some room treatments instead. If not, porous flat paint will definitely improve your sound reflection problem.

Roy, the H.D. paint guy