Okay, this is weird. I played the disc again (the same one from before) today, and I worked, and as I played it from beginning to end, nothing wrong happened. "shrugs" I don't get it.
I had problems with PowerDVD awhile back playing newer BD discs and went to Total Media Theatre 3 which I've had for some time. Oddly enough, this older software had an update still available which corrected the problems, similar to yours, I was having.
Then see if Cyberlink has any updates for the PowerDVD version you have; that may correct the problems.
You might try a different player as well, perhaps WinDVD.
Is Total Media Theatre 3 free to get? If so, where? Same goes for WinDVD, and the update for what I have. Speaking of Cyberlink Power DVD: anytime I look for an update, it's one that costs money. If there was a free one, that'd be great.
You may also need to check if there are any firmware updates available for your external BD drive.
I did what you asked, but I'm not too sure if I have any or if I'm looking at it right, and I don't want to click something that's wrong. I made a picture so you can pinpoint it for me, here: