This happened to my best friend last night and pointed me to this link when he did some research. Just passing it along.
Originally posted by ArticleUnfortunately, gamers eager to sample the cel-shaded beat-'em-up were in for a very nasty surprise. That's because the demo contained a glitch that will erase all saved games on the memory card or cards currently inserted in the console.
DSiWare (Monday, April 27) - Clubhouse Games Express: Card Classics (500 points) - Paper Airplane Chase (200 points) I played Paper Airplane Chase when it was included in WarioWare. It was cute. Not worth-money cute, but cute.