I'd like to chime in and say that the cheat/patch thing floating around the web (the XPA one) did work for me on a 1.4E DSi and an Acekard 2i. European DSi updated to latest firmware, if that matters at all.
However, it only worked after I put the latest AKAIO Firmware on the card. It did not work using the official firmware (or at least not with the version I had, maybe they updated it by now). So far I've been able to play about 5 hours into the game without problems (just did the part with the Giga-Carrot or what that was) but of course I still don't take it completely for granted I won't run into any problems along the way.
I do get "flickering" on the upper screen sometimes (when I get these Special Attack puzzle pieces or when saving, for example) but it hasn't caused any problems so far. My saves are also persistent and can be loaded fine. I did play pretty much non-stop (fun game) and didn't have any freezes, glitches or bugs so far.
So, if you have an Acekard 2i and a DSi and can't seem to get it working with whatever Firmware you currently have on the card, try putting the latest AKAIO on it (I got the repacked thing from the download section here).
I also can't play Portrait of Ruins without the usual freezes on the card so it's not a particularly fast one (might be what's causing the flickering in M&L3)
Sorry if this all has been said already. I did notice some people saying it worked on their Acekard 2i, but didn't get it to work on mine. One of them said he had AKAIO though, which I didn't, so I tried it out and it did in fact work.