Michael this was a brand new disc out of the box but after the first lockup I did take a look at the disc and didn't notice anything unusual but still wiped it anyway, the second lockup occurred at the exact same time (:57:20) at which time I just parked it. We watched about half of the SD-DVD POTC 'At Worlds End' this evening without nary the first hitch.
No problems with any of the other HD disc we've watched but we have had it skip a couple of times with at least three SD movies we've watched. Whenever we were watching the SD-DVD version of The Aviator it started skipping quite often, I rebooted the A2 and everything was fine during the heavy skipping parts and for the remainder of the movie.