there are two versions of firmware - UMS (player is working as pendrive) and IMM (player needs iriver Music Manager 3.17 to work)
READ THE DESCRIPTION of firmware, so you won't be surprised...
http://www.iriver.com/html/support/d...hProductIdx=34
what is important is that:
- you can "upgrade" from any firmware to any - no matter what are the numbers or "versions", without restrictions
- after changing versions you need to format player:
-- UMS -> IMM - format from iriver Music Manager (there is icon at the bottom of "player window")
-- IMM -> UMS - format from My Computer