Yes, SNEmulDS is the best emulator for the Nintendo DS (unless you had a Supercard DSTwo, which have a better emulator).
According to the compatibility list: "SMW will work fine until the boss battles. Some minor graphics glitches and sound gargles. HUD not entirely visible. Use v0.6 WIP2 and use Squish HUD to fix the HUD. (use BG1:3 BG2:3 BG3:0)." But I never had that kind of problems.
Maybe, if you download this rom "Super Mario World (U) (V1.0) [!]", you fix it.