Running Parallels Build 3214, so please let me know if the Upgrade V3 has solved this usb limitation. My use of Windows XP is primarily hardware control applications that cannot be run in OS X due to software availability. These applications are low speed and all work properly in Boot Camp and seem to work properly in the competitors Beta VM. As soon as I connect a 4 port USB to serial box (Whiteheat) and an IO Gear USB to serial converter, the system will not allow any other USB devices including Apple USB Modem, Apple Wireless, Apple IR Receiver and/or anything else plugged in the USB ports with the correct drivers installed to be used with the Parallels VM. I do not know if these limitations permit a single USB device interface (MicroHam MK2R+) that creates up to 10 serial ports with Windows XP driver which allows other Windows software to interface with each of these virtual serial ports to control the radio hardware. Why does the virtual machine have to have such severe limitations on USB usage (and serial ports) when Windows inherently has no limitations?