One nice thing about the 990's AV sync settings (which you likely have already noticed, but is still worth noting here) is that each video input has a separate sync setting - so if the DVD player introduces more delay than the HD cable box, you set the DVD input to one thing and the cable input to another. Obviously, if the source experiences different delay under different circumstances (such as a local TV station that can't seem to get their HD broadcasts to sync up correctly most of the time), this is less effective, but nothing short of a fix at the source is likely to help there...