Plasma 42 inch ....

Yes, you're right sorry, I meant the exact opposite of what I wrote, duh! My consistent sync problem is that the sound comes out before the video, and there is no video delay in components that I've seen... I have audio delays set on my components set to zero, so I'm not sure where the problem is.

If the sound comes out before the video, then you want to set your audio delays to something greater than zero, so that the audio is delayed.

If I set a delay for the audio, it only makes things worse because that is my problem - audio before video. I need a delay for the video, but I'm not sure if that is even possible...

No, if your problem is audio before video, then what you need to do is delay the audio to allow the video to catch up. If setting the audio to delay makes things worse as you say, then your problem is video before audio. But I'd be surprised if that's the case. Try playing with different degrees of audio delay again and see if you can't find a setting that works.

The problem I've found is that the degree of delay varies not only from source to source but from channel to channel and DVD to DVD. Even worse, some people claim there is variation within given DVDs.

Yup, you're absolutely right, I think I must have been trying a delay that was way too high, setting to 10ms seems to improve things. Unfortunately I only have this setting on my DVD player, and not on my preamp...