Though I think it's somewhat late (4 years later from the last post!)
Pressing SELECT while loading the song(=right before the actual game) toggles HI-SPEED option.
After that, press up and down to change speed.
Actually there's a more simple way to boot NDS menu w/o removing the card when you use YSmenu.
Just press START button and choose 'DS menu'.
Passme and GBA cartridges can be booted by this way, too.
Hope this helps.