Unfortunately libusb-win32 seems to have a more direct access to the USB stack than USB Monitor ( http://www.hhdsoftware.com/Products/home/usb-monitor.html ), so libusb-win32 based USB usage is inivisible for USB Monitor, which makes debugging a little bit hard. Is there some possibility to ensure that the traffic generated with libusb-win32 based applications can be recorded by USB Monitor?
Had the same issue... Did you ever figure that out?
You can use DebugView.