PQI 128MB USB flash drive mount problems

hi,

i have a PQI Intelligent Stick 128MB USB flash drive that
i'm trying to get working on -CURRENT.

i added:

  device da
  device scbus
  device umass

to my kernel configuration.

when i attach the drive, it detects it correctly, and
i get the following kernel messages on the console:

umass0: Intelligent Stick Intelligent Stick, rev 1.10/1.00, addr 2
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <USB Card IntelligentStick 1.00> Removable Direct Access SCSI-0
device
da0: 1.000MB/s transfers
da0: 127MB (260448 512 byte sectors: 64H 32S/T 127C)
umass0: Phase Error, residue = 0
(da0:umass-sim0:0:0:0): Synchronize cache failed, status == 0x4, scsi
status == 0x0

after the above is printed, it prints:

Opened disk da0 -> 5
Opened disk da0 -> 5
Opened disk da0 -> 5
Opened disk da0 -> 5

4 times, and then it appears to give up. any attempt to mount
/dev/da0s1 fails after a timeout of about 15-20 seconds or so.

ash# mount -t msdos /dev/da0s1 /mnt/istick
msdosfs: /dev/da0s1: Input/output error

any ideas what to do to debug this? given pointers, i'm willing
to play with some code.

thanks!
leon

nb: please cc me on responses.