can't record sets on XDJ-RX

hi there! 

as the title states, i can't save sets on my XDJ.

it was working fine a month ago, then i wasn't getting the PIONEER-REC folder at all. so i formatted the USB a thousand times (FAT) until the folder was showing up, reinstalled the firmware, and assumed i was good to go. then i recorded a set (yes the red light was flashing) and came home to an empty folder. 

any ideas?

thx!