Lip sync delay question

I have one DVD player hooked up to the dvd input and the lip sync delay works fine. I want to hook up another dvd player up and wanted to use the AUX input and then rename it DVD2, but it will not let me activate the lip sync delay in the menu. Do I have to use one of the video inputs and then rename it?
I have the video from both dvd players going straight to my projector and am not using any of the video switching on the 990. Thanks.

Aux is an audio input, and as such has no video source associated with it. With no video source comes no lip sync delay. You'd need to one of the video inputs for the second DVD player.

That's what I thought. No problem there. Thanks Gonk.