I had a weird lip sync issue when I first set up my 990. As Altec stated generally lip sync issues happen due to the difference in processing time for audio vs. video and almost always it is the audio that is presented ahead of the video. However, in my case I was actually getting the audio behind the video, which meant the 990 could not adjust for it correctly. After digging around and speaking with Scott at Outlaw I discovered that it was due to a bad auto calibration. I know this sounds weird but when I went and looked at the the delay settings there would be a very strange value set for the sub's distance. Once I set that to an appropriate value the lip sync issues were resolved.

In reviewing the other posts I noticed that Skyblazer was also able to resolve lip sync issues with a recalibration. I suspect that he was having the same problem that I was having.

So just for grins, take a look at the delay settings for your speakers and see if the sub's distance is set to something that looks obviously wrong and if so correct the distance and see if that fixes the problem.