Multiple keyboards and trackballs

Hi,
I am trying to install two keyboards and two trackballs on my new system. I need the second keyboard and trackball in order to be able to control my computer from my drumset which is about 10 feet away from my desk. This worked fine on my previous system.

Previous system
Keyboard 1 on PS2 port
Trackball 1 on PS2 port
Keyboard 2 and Trackball 2 sharing one USB port

Current system
Keyboard 1 on USB port
Trackball 1 on USB port
Keyboard 2 and Trackball 2 sharing one USB port

I think, but dont know how to confirm, that there is a problem with multiple human interface components on USB. Does this make sense and how do I prove it definitively?


Current System
Windows XP Pro Service Pack3
Intel DP45SG motherboard
Intel Core2 Quad processor 2.8
4 gigs of RAM


The motherboard only has USB ports, there are no PS2 ports so I have to find a solution for this. Any help or advice would be appreciated.

Another note. If I boot the system with the secondary keyboard and trackball plugged in they do not start. However if I plug them in after XP comes they work. This might work except that getting to the rear of the machine is not that easy.