I just tried connecting my son's MP3 player to NetBSD, both 1.5.2 and 
-current.  The device was recognized as a mass storage device by the 
kernel, but attempts to talk to it failed:

umass0 at uhub0 port 1 configuration 1 interface 0
umass0: Frontier Labs     NEX II Digital Audio Player   , rev 1.00/0.01, addr 2
umass0: using SCSI over BBB-P
scsibus0 at umass0: 2 targets, 1 luns per target
scsibus0: waiting 2 seconds for devices to settle...
sd0 at scsibus0 target 1 lun 0: <FL, Nex II Digital, 0001> SCSI0 0/direct removable
Nov 28 20:43:26 berkshire su: smb to root on /dev/ttyp4
umass0: BBB reset failed, STALLED
umass0: Invalid CSW: tag 118 should be 119
umass0: BBB reset failed, STALLED
umass0: Invalid CSW: tag 119 should be 120
umass0: BBB reset failed, STALLED
umass0: Invalid CSW: tag 120 should be 121
umass0: BBB reset failed, STALLED
umass0: Invalid CSW: tag 121 should be 122
umass0: BBB reset failed, STALLED

etc.  Any suggestions?

		--Steve Bellovin, http://www.research.att.com/~smb
		Full text of "Firewalls" book now at http://www.wilyhacker.com