i use a 2gb sandisk one. i formatted it to FAT32 and it works great every time
i have about 9 diff roms that differ in about 5 diff groups....at my disposal to flash to during the day.
i wish my 4gb micro-sdhc would work, but it wont. i may have to remove everything off it, format it to fat32, and then move all my files back over and see if it works
or i may just buy a 8gb
12gb is almost out