The bootleggers annoy me to no end. I just got a used copy of the newest Prof. Layton off Ebay for ~$19 shipped, and it didn't say anything about not working on the DSi. Heck, the lady/guy told me they got it at Wal-Mart. My BS detector goes off when the package comes and it's in one of those huge ass white cases. Of course it has the usual differences on the cartridge as well (the green below the bronze 'teeth' instead of all black, the spacing between the Pat Pending and the black inked serial, etc) and won't play in my DSi. Finally thought I was safe buying not only from an American address, but from one where there was no mention of 'NOT for DSi' and (due to the description) obviously from someone's personal collection. Guess not.
I figure the person may be BSing me, saying they "got it at WalMart for my spouse and it played fine," though I can't be sure. The person doesn't have much feedback, but I looked at it and there are apparently quite a few legit games on there (PS3/PS2 games) so this seller could have honestly just not known jack shit about it, but it still begs the question: bootlegged games in Wal-Mart in those ridiculous clear cases? (I guessed it was a possibility due to return fraud perhaps?) Also, oddly enough, I think this particular seller suspects ME of BSing. Even if he was playing stupid though, I explained to him the huge ass ways to spot an obvious fake (starting with the damn box and manual) and how they would play on the DS/DSLite, but not the DSi. I have a friend with a DSLite though that offered to pay me for the game, exactly what I paid for it. The guy doesn't take returns, and I managed to find a slightly more expensive used copy from a rather reputable seller.
*I apologize for the mini-rant, but I've never actually gotten a bootlegged game from an AMERICAN address. I expect it when I see $15-16 copies of NEW games shipped from Hong Kong or elsewhere in China. Hell, I bought a cheap (and obviously bootlegged) copy of Sonic Chronicles back before I even knew about bootlegged DS games (which is how I knew all the telltale signs; I took out my Sonic Chronicles case and cartridge and compared them with the Layton case/cart) but even those bootlegs now say that they can't play in the DSi.*