Fun fact: Blowing on the cartridge does all of jack shit. The game glitching out when you start is up is pretty much always due to poor contact between the console and cartridge. The act of removing and replacing the cartridge is often what fixes the problem, with the blowing being nothing more than a placebo.
Tell that to my DSi =_=
Remove cartridge, place it back in, play...
Nope.
Remove cartridge, place it back in, play...
Nope.
Remove cartridge, place it back in, play...
Nope.
Remove cartridge, blow, place it back in, play...
Ba-ding!