[Libusb-win32-devel] usb_claim_interface : invalid argument

[Ben <bn...@ya...>]

Hello

I am trying to use libusb on WinXP
to operate ftdi chip in bitbang mode.
I've created inf file and successfully
installed the device driver (not filter driver). 
Using supplied test program I see the device. 
But when  I run my program usb_claim_interface
fails. I've checked that no other drivers
use the device.  What actually happens
is that DeviceIoControl inside  usb_claim_interface
returns error with description "invalid argument".
The same code works fine on Linux.
Do I need administrative
privileges  to use libusb ?

thanks