If changing the resolution stops the pop-up, go for it. It will not affect the S-video output.
I have the same setup on one of my TVs and it works perfectly. You just have to convince the receiver that you are watching HD (such as on the component cables) by setting the output resolution to 720p/1080i and even if the cables are not connected the receiver will not know the difference, so will stop giving you the messages.Supervolcano said:Ya, change the resolution to the best your tv can accomidate.
The popup will never appear again.
The svideo jack (and yellow composite jack as well) only outputs 480i, meaning it DOWN CONVERTS the program, no matter what higher resolution it might be.