GA-EP45-UD3P won't boot when KVM is connected + other USB

I have a Q6600 CPU on a GA-EP45-UD3P motherboard.
Also have a four-port IOGEAR DVI KVM.

Everything was working fine until recently. Suddenly, my computer will not complete POST whenever the KVM's USB is plugged in when I have any of my wireless mouse or keyboards also plugged in.
If I unplug every USB port except the KVM, then the computer powers on fine.
If I plug in more than one or two of my wireless USB devices (keyboard & mouse), then the computer gets stuck in POST before it can initialize the hard drives.

If I unplug the KVM and plug in every other USB device, everything works fine. It's only a combo with the KVM USB when I start to encounter POST issues.

Any ideas?

All firmware is updated.
I cleaned out all the dust and blew out all the ports.