Just bought a USB2 Freecom Classic Hard Drive (250GB). Both 2.0.2 and 
3.0_BETA give a cycling list of errors such as "BBB reset failed", "BBB 
bulk-in clear stall failed", etc. The problem is the same with FreeBSD 
5.4. I've blindly tried a few quirks from rooting around Linux and *BSD 
mailing lists, but not got anywhere.

Portion of output from UMASS_DEBUG below (further details on request):

umass0: umass_scsi_cmd: at 14.635839: 0:0 xs=0xc0fa6000 cmd=0x25 datalen=8 (quirks=0x8110, poll=0)
umass_scsi_cmd: async dir=1, cmdlen=10 datalen=8
umass0: umass_bbb_transfer cmd=0x25
umass0: CBW 44: cmdlen=10 (0x25000000000000000000), data = 8 bytes, dir = in
umass0: start xfer buffer=0xc0fa4868 buflen=31 flags=0x0 timeout=25000
umass0: Handling BBB state 1 (BBB CBW), xfer=0xc0f27e00, NORMAL_COMPLETION
umass0: start xfer buffer=0xc7eb8000 buflen=8 flags=0x5 timeout=25000
umass0: Handling BBB state 2 (BBB Data), xfer=0xc0fa3700, NORMAL_COMPLETION
umass0: BBB_DATA actlen=8
umass0: 0x 1d1c597000000200 buffer=0xc7ecbc6c, buflen=8
umass0: start xfer buffer=0xc0fa4887 buflen=13 flags=0x0 timeout=25000
umass0: Handling BBB state 4 (BBB CSW, 1st attempt), xfer=0xc0fa3500, NORMAL_COMPLETION
umass0: CSW 44: sig = 0x53425355 (valid), tag = 44, res = 0, status = 0x00 (good)
umass_scsipi_cb: at 14.640600, delta=4761: xs=0xc0fa6000 residue=0 status=0
umass_scsipi_cb: at 14.640600: return xs->error=0, xs->xs_status=0x0 xs->resid=0
umass0: umass_scsi_cmd: at 14.640936: 0:0 xs=0xc0fa6000 cmd=0x5a datalen=16 (quirks=0x8110, poll=0)
umass_scsi_cmd: async dir=1, cmdlen=10 datalen=16
umass0: umass_bbb_transfer cmd=0x5a
umass0: CBW 45: cmdlen=10 (0x5a000000000000001000), data = 16 bytes, dir = in
umass0: start xfer buffer=0xc0fa4868 buflen=31 flags=0x0 timeout=11000
umass0: Handling BBB state 1 (BBB CBW), xfer=0xc0f27e00, NORMAL_COMPLETION
umass0: start xfer buffer=0xc7eb8000 buflen=16 flags=0x5 timeout=11000
umass0: Handling BBB state 2 (BBB Data), xfer=0xc0fa3700, NORMAL_COMPLETION
umass0: BBB_DATA actlen=8
umass0: 0x 00060000000000000000000000000000 buffer=0xc7ecbcc4, buflen=16
umass0: start xfer buffer=0xc0fa4887 buflen=13 flags=0x0 timeout=11000
umass0: Handling BBB state 4 (BBB CSW, 1st attempt), xfer=0xc0fa3500, STALLED
umass0: Failed to read CSW, STALLED, retrying
umass0: Clear endpoint 0x82 stall
umass0: Handling BBB state 5 (BBB CSW bulk-in clear stall), xfer=0xc0fa3300, STALLED
umass0: BBB bulk-in stall clear failed, STALLED
umass0: Bulk Reset
umass0: Handling BBB state 7 (BBB Reset), xfer=0xc0fa3200, STALLED
umass0: BBB reset failed, STALLED
umass0: Clear endpoint 0x82 stall
umass0: Handling BBB state 8 (BBB bulk-in clear stall), xfer=0xc0fa3100, STALLED
umass0: BBB bulk-in clear stall failed, STALLED
umass0: Clear endpoint 0x01 stall
umass0: Handling BBB state 9 (BBB bulk-out clear stall), xfer=0xc0fa3000, STALLED
umass0: BBB bulk-out clear stall failed, STALLED

-- 
Stephen