E6500 won't see USB mouse/keyboard on initial boot

I have a Latitude E6500 with a docking station that shares a monitor,  USB mouse and keyboard with a couple of other systems via a Belkin KVM (SOHO model).

The problem is this. When powering it up while in the docking station, I can see video on the external monitor, but the keyboard and mouse will not respond.

So here's the process I have to go through to get everything to work:

1. Power up laptop

   a. video on monitor but no mouse or keyboard from the KVM. Unplugging/replugging the USB does nothing.

2. Lift the lid of the laptop

   a. now I have video on laptop and monitor

   b. I have working mouse, keyboard etc on KVM as well as laptop

3. Close the lid of the laptop

   a. system goes into sleep mode

4. Hit power on docking station to wake laptop

   a. I now finally have the mouse and keyboard working via the KVM with the laptop closed.

I suppose I could stop after step 2, and leave the laptop open all day, but come on...

This shipped with Vista, but I have downgraded to XP (32-bit) to comply with our corporate standard. There are no unresolved driver issues, at least according to Windows Device Manager.

Any thoughts as to what's going on here?

Thanks!