be sure your cables are less than 6 feet long, and that they're shielded. cheap cables aren't shielded and you get "noise" in the lines, causing blur on the video. you might look into getting the latest drivers for your video or even getting a higher-quality vid card...that will solve your problem, imo. I have a kvm switch and no problem on either of my two systems...using 6' long (manufacturer's recommendation not to exceed this length) kvm cables, and no problem. watch that your cables don't fall too close to the monitor...the magnetism can cause interference.
~Branson