LG 1720P DVI input broken; VGA input still works?

I recently swapped out a Samsung CRT for a Samsung 215TW to go along with my LG L1720P, both on DVI connected to my Gigabyte GeForce 7600 GT card. When I rebooted after installing the Samsung software, the LG would no longer work via DVI; it only works via VGA. I tried both outputs on the GeForce, I tried two DVI cables, and tried the LG on my old PC with an ATI DVI card, and it looks like the LG's DVI input is shot (the screen says "Digital - Power Save Mode", then the monitor goes into standby). The VGA input works (via a DVI-VGA adapter). The LG's DVI input worked fine until I added the 215TW to the mix.

Is it common for a monitor's DVI input to break while the VGA input still works? What can cause this to happen? Can software break a monitor's input? Or could it just be a strange coincidence that the input broke at the same time I installed a new monitor?

Thanks,

- Chris