ftdi usb-serial converter driver issue

Good morning,

I am stuck at a new driver for a ftdi usb-serial converter, what happens is the urb status is always EBUSY for the bulk write, I have read the ddk and consulted the expert, but still could not move on, if you could point me a direction that might help, please post here or send to zhourb@gmail.com.

BTW, I am using the printer driver as the starting point, and also tried to write from scratch, both drivers I have now stuck at the same place for me.

Thanks a lot.