Nintendo 64 and DS Games for Wii U Virtual Console

The emulation of DK64 runs OK, but the sound emulation isn't perfect. Some sound effects sometimes play up to 3 seconds late, and sometimes, background music won't start up, this is especially noticeable when going from one area to another, when the music is supposed to fade from one track to another and on starting bonus stages. The latter only happened to me a select few times, but sound effects arriving late happens regularly.

Hey has anyone played Mario kart DS Emulated on Wii U how does it play ???