Jason, what do mean by layer breaks? I've noticed that it doesn't take much of anything to have either one of our Sony MegaChangers skip, the least little scratch or dust and they will skip.
On SD movies they have put so much extra crap on the movie disc that the DVD's are built in layers so there are actually 2 layers of reading material on the disc. Now when a player reaches the end of the first layer it is supposed to sync up to the next layer but if the laser has a hard time reading through to the second layer the player will hiccup or just stop until it figures things out.
This is what made me start backing up my discs because the software out there will remove the layer break points and burn just the movie to a single layer disc. You also loose some of the video signal on long movies but on a 480i screen it can get as low as 70% quality before it is noticeable, at least for me. I have played back my back ups on higher res TV's and unless it was burned at 100% they look terrible.