I’m almost certain that this work around will fix the issue with IOGear KVM switches not working properly with nForce 4 chipset motherboards.
You know that add on USB port you receive with your motherboard? The one that plugs in to the motherboard USB header? I have that connected and installed into my case and I was using the IOGear MiniView USB KVM switch which apparently is not supposed to work directly with any nForce 4 chipset motherboard unless you’re using a PCI USB card and or a USB hub. I guess not many people bother to install that extra piece that comes with their computer. It worked for me and I don’t see why it won’t work for you.
I was able to switch between multiple computers, turned my machine on, off and then back on again. Rebooting was no problems. Not once did I experience the erratic mouse behavior that everyone describes. I hope this will help you out!