Thanks frogboy for clearing that up,that was my only concern about it not fitting... im getting the Acekard 2i...im going to get it from zhu zhu as well ..
Thanks
It should always fit, the paper trick is used when the PCB that holds the contacts flexes slightly, and the contacts of the AceKard2i can't 100% come in contact with the ones in your DS system. If you stick a small piece of paper behind the contacts in the card, it pushes them out ever so slightly, but just enough to resolve almost all contact issues (which would involve freezing during gameplay, freezing while booting the card, system not recognizing the card, and some others).
As far as cards that "don't fit", the only ones I've seen are ones with a window for an extra chip sticking through. My old iTouchDS RTS did it, but that card sucks and is 100% irrelevant... however, the Supercard DSTWO does it also, as the extra on-board CPU does stick through a window slightly. All this means for you is that the card is a bit harder to insert and take out. I've had my DSTWO for well over a year now, taken it out and inserted it many times, and nothing is damaged, card or DS wise.
I will warn you, if you're using any of these (or even original DS carts) on a 3DS, make sure you insert them straight and not at an angle, I've heard a few reports of the pins catching on the teeth and bending in the 3DS when the card isn't going in straight enough.
Edit - and the AceKard2i is a good card. I got one for my little brother for christmas, and I love it. The new ones don't have any chip sticking through a window, so they fit just like an original cart.