should I try unmounting the FAT partition manually? I think that is "umount /media/mmc2" (maybe as root?). But if that works, how do I mount it again after I finish? (without rebooting, that's what I'm trying to avoid).
Is no one else having this problem?

edit: Is "mount vfat /dev/mmcblk0p1 /media/mmc2" the command to mount it again?