USB umass problem

Hi, everybody!

I have a troubles using my USB2.0 TwinMOS flash drive with -current.
It is attached
Jan 18 18:51:48 yb3791 kernel: umass0: TwinMOS-TTI USB 2.0 Mobile Disk, rev 2.00/1.00, addr 2
Jan 18 18:51:48 yb3791 kernel: GEOM: create disk da0 dp=0xc3819850
Jan 18 18:51:48 yb3791 kernel: da0 at umass-sim0 bus 0 target 0 lun 0
Jan 18 18:51:48 yb3791 kernel: da0: <USB 2.0 Mobile Disk > Removable Direct Access SCSI-2 device
Jan 18 18:51:48 yb3791 kernel: da0: 1.000MB/s transfers
Jan 18 18:51:48 yb3791 kernel: da0: 246MB (503808 512 byte sectors: 64H 32S/T 246C)

and mounted correctly, but attempts to read or write it can cause a hangup of
userspace process in D state with a lot of messages from kernel:
Jan 10 18:02:51 yb3791 kernel: umass0: BBB bulk-in clear stall failed, TIMEOUT
Jan 10 18:02:56 yb3791 kernel: umass0: BBB bulk-out clear stall failed, TIMEOUT
Jan 10 18:03:06 yb3791 kernel: umass0: BBB reset failed, TIMEOUT
Jan 10 18:03:11 yb3791 kernel: umass0: BBB bulk-in clear stall failed, TIMEOUT
Jan 10 18:03:16 yb3791 kernel: umass0: BBB bulk-out clear stall failed, TIMEOUT
Jan 10 18:03:26 yb3791 kernel: umass0: BBB reset failed, TIMEOUT
Jan 10 18:03:31 yb3791 kernel: umass0: BBB bulk-in clear stall failed, TIMEOUT
Jan 10 18:03:36 yb3791 kernel: umass0: BBB bulk-out clear stall failed, TIMEOUT
Jan 10 18:03:46 yb3791 kernel: umass0: BBB reset failed, TIMEOUT

I have tested it on some hardware and I could not reproduce the problem on motherboards with
KT133A, i845 and i865 chipsets, 
but it happens almost every time on my home PC with KT333 (south bridge vt8235) motherboard.

Writing to usb drive usually causes hangup almost immediately (1-2 s) whereas reading from it
could be smooth for a quite long time (10-20 s).
When hangup occurs during reading, kernel messages looks like: 
Jan  8 08:14:18 yb3791 kernel: umass0: BBB reset failed, STALLED
Jan  8 08:14:23 yb3791 kernel: umass0: BBB reset failed, STALLED
Jan  8 22:32:35 yb3791 kernel: umass0: BBB reset failed, STALLED
Jan  8 22:32:50 yb3791 kernel: umass0: BBB reset failed, STALLED

I tried to compile kernel with/without ehci support but had not noticed any changes.

Of course, "it works under windows" on the same hardware.

It's probably not my personal problem, there are some messages mostly in freebsd-current
maillist describing very similar problems. (Last was 11.01.2004)

Any ideas/suggestions? Where I should dig?

Best regards!
Yan