USB Printer driver for win2k

Hi,

I am developing a USB printer driver (language monitor)for a printer.
I am encoutering the following problem.

Readport command fails, but I am able to write to the port
through USBMon.dll, the port monitor provided my microsoft.

But when I bypass USBMon and talk directly to USBPrint.sys I am
able to perform both ReadPort and WritePoprt.

But ReadPort works under win98 and winXP.

I tried to debug usbmon using soft-ice and I believe usbmon’s
createfile function fails.

Has anyone encountered this problem before?It would be of help
if someone could provide a lead.

thanks,
gibb