pl2303 USB Serial Device Problems

[Keith]

I have connected this device as root and I have run all commands as
root,
but i get numerous errors from this device.



dmesg
[17180102.492000] usb 2-1.2: new full speed USB device using ehci_hcd
and
address 7 [17180102.584000] usb 2-1.2: configuration #1 chosen from 1
choice [17180102.584000] pl2303 2-1.2:1.0: pl2303 converter detected
[17180102.588000] usb 2-1.2: pl2303 converter now attached to ttyUSB0
[17180256.624000] pl2303 ttyUSB0: pl2303_open - failed submitting
interrupt urb, error -28


ls -l /dev/ttyUSB0
crw-rw-rw- 1 root dialout 188, 0 2006-11-13 07:02 /dev/ttyUSB0

minicom
minicom: cannot open /dev/ttyUSB0: Protocol error

/proc/bus/usb/devices
T:  Bus=02 Lev=02 Prnt=02 Port=01 Cnt=02 Dev#=  7 Spd=12  MxCh= 0 D:
Ver=
1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1 P:  Vendor=067b
ProdID=2303 Rev= 3.00 S:  Manufacturer=Prolific Technology Inc. S: 
Product=USB-Serial Controller
C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA I:  If#= 0 Alt= 0 #EPs= 3
Cls=ff(vend.) Sub=00 Prot=00 Driver=pl2303 E:  Ad=81(I) Atr=03(Int.)
MxPS=
 10 Ivl=1ms E:  Ad=02(O) Atr=02(Bulk) MxPS=  64 Ivl=0ms E:  Ad=83(I)
Atr=02(Bulk) MxPS=  64 Ivl=0ms


Thanks for any help or pointers.