PodBoy's test is a good one, and as he suggests it is possible for a disc to be improperly mastered such that a sync error exists on the disc itself. I've heard of this happening, but I don't recall it happening with a major commercial release. There have been studio releases with comparable mastering problems before, of course, but in those cases the studio has typically acknowledged the mistake (usually due to significant internet-based consumer complaint) and re-issued the disc.