Monitor interference help

[lsjreadingpa]

Im having an issue with something causing interference with my monitor. This my setup: I have my computer and my xbox hooked up to my monitor with a KVM switch, i have a 2.1 speaker system and this is all next to my tv. I have unplugged my speaker system and my xbox to see if either of those are the issue, no difference. I have also unplugged all usb devices as well and still no change. The only time i get no interference is when i have my xbox on and my computer off, the monitor is free of interference. I need new ideas to fix my monitor issues, please help!

 

[Tmagic650]

The KVM switch may be causing the video interference. Are you using a standard VGA video cable or adapter?

 

[lsjreadingpa]

2 vga cords one from the computer one from the 360. But here is the odd thing, if i have the pc off and the 360 on the interference goes away ; /.