Did Apple Break HD-DVD Playback with Mountain Lion using Apple DVD Player?

First of all, kindly spare me the commentary about Blu-Ray beating HD-DVD. Agreed and not the question. I have perfectly good reasons for using HD-DVD and it works very well for my purposes.

I authored an HD-DVD in DVD Studio Pro 4.2.2. as I have done many times before on Snow Leopard, but this time on Mountain Lion. When I try to play the HD-DVD, either from the physical disk from a disk image, the menu appears, but when the play button is pressed, the menu stays on screen, but the player shows the timecode of the movie playing, but with no sound or picture.

Thinking that perhaps the menu got corrupted, I put the same HD-DVD into a MacBook Pro running Snow Leopard, and it played perfectly! Conclusion: Not a DVD Studio Pro problem.

Thinking that it might be DVD Player, I copied DVD Player 5.4 from the Snow Leopard MacBook Pro to the Mountain Lion MacBook Pro (which was running DVD Player 5.6), and the HD-DVD still had the same issue on the Mountain Lion MacBook Pro, under either of the DVD Player versions. Conclusion: Not a DVD Player issue.

The HD-DVD does mount and initialize, so it's not a hardware issue with the optical drive.

Conclusion: It would appear to me that it's an OS issue with Mountain Lion breaking (either intentionally or unintentionally), HD-DVD playback. Anyone know anything more about this issue? Anyone else saddened to see Apple turn into Microsoft circa 2005, and the MacOS turn into Vista? I haven't seen much of anything about it in the forums, which is why I'm posting it here.

Thanks Apple. I just spent the better part of 3 days transcoding and authoring this HD-DVD, only to have you screw it up for me 2 days before my film festival (the perfectly good reason for using HD-DVD). Kindly spare me the, "Why don't you encode a ProRes blah blah blah quicktime movie." Heard it all before.

I knew I would regret upgrading to Mountain Lion, and I do more and more each and every day as I continually find more things that it broke. Yet another reason to add to my list for downgrading to Snow Leopard. I'm up to about 30 of them. Or to abandon Final Cut for Adobe products.

Thanks and sorry for the rant, but I'm justifiably frustrated.