That sounds fairly logcial, as it should work. If you're using a serial port and PS/2 port, they become two seperate devices. Pointing devices or not, they're still two seperate devices. By the same logic, if they didn't work, then if I plugged my Sidewinder Force Feedback Joystick into the game port interface, and my USB Gamepad into a PS/2 interface via a USB/PS-2 converter, then neither of the devices should work simultaneously. ZSnes picks them up as two seperate devices, and can be mapped individually. So... yeah.