Mouse Behavior in XP

Hi,

I have just re-installed Windows XP Pro. I have an Intellipoint
Optical mouse, hooked to a KVM.

Ever since I reinstalled Windows, whenever I try selecting text with
the mouse and typing at the same time, or if I am typing and move the
mouse, I get weird behavior from Windows.

My window may lose focus, or different menus may pop up, or if I am in
IE, I may go back a screen or two.......it is just ANNOYING!

I cannot find anything on this. I updated Windows with all the proper
drivers, yet the problem still exists.

A bit more on my hardware:

ASUS A8N SLI-Deluxed Motherboard
AMD x2 Dual Core 3800 Processor
1GB Corsair DDR 3200 400mhz Memory

Any thoughts on why this started happening?

Thanks,

Arthur