Ok guys, I was very intressed in this post as I recently bought a M3 Ds Real (a white -Chinese region) for my daughter by mistake (website didn't mention this..). Here is what I did and it works.
First go to:
http://www.handheldsources.com/M3DS/Download_M3DSR.htmland download the latest versions of the firmware for your card (both the Chinese version and the English version), latest version of firmware is:
M3 DS Real Firmware Version 3.7f (release-date: 3.jun2008), and unpack. (and of course download the patcher)
I first checked if my card worked with the downloaded Chinese firmware (and it did), so all buttons are in Chinese. Meaning my card works the sys-file named: g6dsload.gb (you will need to know this to use the patcher, so you know with region to chose when you use the patcher)
Now just follow the instructions made with the patcher (patcher only works with xp-machine NOT vista (the patcher shuts down)).
Once you have a patched sys-file: g6dsload.gb replace the original one in the firmware with this one.
Once you restart your DS with the M3 you will be able to chose with language you want to run (English works...)
So for those intrested, yes the patcher works with the latest firmware.
I can not thank you guys enough for helping me