KVM switch and Mac Pro

I just got my Mac Pro, I am coming from a PC platform. I am a professional photographer and as such store a lot of images. I currently have a PC server that has lots of disk space on it. Since I have two PC's, I have used a KVM switch to go between them. I tried hooking the Mac Pro up to the kvm switch. I am using the DVI to VGA adapter, when the Mac Pro starts up, my mouse ( Microsoft Wireless) almost fails to respond. Oddly, it seems it is the video connection on the Mac Pro that causes this. When I unplug the video, the mouse starts responding. I really don't want to do the two keyboard, mouse and video thing.

Any ideas on this?

Kristi