Have you guys ever had issues with your DS? Possibly the same one I'm having?

Sometimes when I put a cartridge in my ds it doesn't read it.. it says there is no cartridge inserted into my ds.

I don't know why that is.. Mario kart ds doesn't work in one of my ds's and AC:WW won't work in the other. grah!

I've had that error a couple of times. It fixed itself though by just ejecting the game and then re-inserting it. My guess, at least in my scenario, is that the card wasn't fully inserted properly and causing some kind of connection issue.

But ... I'm guess you tried that, since it sounds like it's happened to you every single time with these games. Maybe there is dirt or dust in the DS where the games go, or maybe even on the DS cartridge? *shrugs*

Hmmm...

I have some DS games that sometimes do the same thing.  The games that will not start up for me feel like the stuff inside the cartridge is loose.  Like, when I shake it i can feel all the components inside it moving around.

Is this the same with your games?

I haven't had a problem similar to what you're experiencing. Though, my "R" shoulder button isn't functioning.