I have a Dell 2500FPW and have it hooked to my PC through DVI and my Xbox 360 through VGA.
The PC part runs fine, and by and large the Xbox does also, but with one caveat. Every few minutes, the display attempts to auto adjust, even though it looks fine. Granted, it's not quite as crisp as I would like, but the Xbox is set to display in 1680 x 1050, which is the monitor's default (native) resolution.
I can't seem to get it to stop, and after you've been killed in multiplayer gaming for the nth time from your monitor randomly going black, it starts to drive you a bit nuts.
This does not happen on the PC, it keeps the image displayed beautifully for as long as I need it, and when other PC's are attached through the VGA input, also no problem. I have tried two different Xbox VGA connectors, to no avail. I have this feeling that it is some setting on either the Xbox or on the monitor that I can't change, that is just out of sync enough to make it do this every few minutes. Any ideas on how to get around this?
I know the sub-category might not fit my query, but at the very least, I am running an Nvidia 9xxx series card with two DVI outs. Was also wondering if I could go VGA to DVI, put it in the PC and have the PC do the switching but haven't had much like finding people with one monitor two input setups like this, most are for multi-monitors...
For added diagnostic awesomeness, I have tried a wide variety of the other available resolutions and had the monitor upscale them. The problem persists! I have the option of using either a 1:1, fill, or to fill while maintaining aspect ratio, all have the same issue, which makes me think it's something to do with either the reference levels, refresh, maybe V-Sync, I am simply at a loss.
If the return policy is equitable, I will try getting a new HD cable from a retailer to find out.