The Sandisk microsdxc 64Gb card was confirmed as working with the Galaxy S2: http://androidforums.com/samsung-ga...micro-sdxc-cards-confirmed-working-sgsii.html Unfortunately, I tested it with MIUI and it didn't work. Specifically, I tested it with MIUI 2.3.9 (based on Gingerbread, not ICS) downaloaded from this site. When I tried to format the sd card with the phone, the phone ended up formatting the internal storage! I also tried formatting the card as FAT32 from the computer, but to no avail. I then installed this version of the stock (rooted) ICS rom: http://forum.xda-developers.com/showthread.php?t=1292825 and the 64gb card worked perfectly. I also managed to reformat it from the phone without affecting the internal storage. Does anyone know: * if this is a Cyanogen problem or only a MIUI problem? * if MIUI on other phones supports 64 GB cards * if the new MIUI 2.3.16, based on ICS, supports 64gb cards?