Extremly slow usb disk

[Björn Johannesson <rherdware%yahoo.com@localhost>]

Hello list.

I just got this external USB HDD enclosure:
http://www.raidsonic.de/en/products/soho-raid.php?we_objectID=7059
It contains two Hitachi Deskstar 7k4000 disks in RAID 1 mode.

At first it did not want to attach at all, it just said:
uhub4: device problem, disabling port 2

It finally probed giving:
umass2 at uhub4 port 2 configuration 1 interface 0
umass2: vendor 0x0dc4 IB-RD4320StU3, rev 2.10/1.00, addr 2
umass2: using SCSI over Bulk-Only
scsibus2 at umass2: 2 targets, 1 lun per target
sd2 at scsibus2 target 0 lun 0: <SV SAFE, , 1.> disk fixed
umass2: BBB bulk-in stall clear failed, IOERROR
sd2: 3726 GB, 16383 cyl, 16 head, 63 sec, 4096 bytes/sect x 976754646 sectors

As you can see it gave an error there. I managed to "label" it with gpt
and made an ffs filesystem on it.
When mounting and using it it gives another
umass2: BBB bulk-in stall clear failed, IOERROR
and
sd2(umass2:0:0:0): generic HBA error

Access to the drive is extremely slow. About 400k/s. Sometimes stalling or 
giving ~20k/s.
Anybody got a clue?

Relevant line from "usbdevs -v":
port 2 addr 2: full speed, self powered, config 1, IB-RD4320StU3(0x020a), 
inXtron, Inc.(0x0dc4), rev 1.00, serial 12060D8301E9
Shouldn't that be "high speed"?

Please CC on reply.

/Björn