Here's the program Schumi-4-Eva wanted to reattach, he said he was having some backup issues though. It fixes the sound problems while your playing the New Super Mario Bros. (US version is only one I tested), havn't really tested it with much else yet.
Unpack to the No$GBA folder.
Run NO$GBA and your game.
Run the "A" program.
I have no idea where this file came from, but it makes NSMB playable with sound, enjoy guys.