Half-dead burner? Can't burn at 8x. And crappy stand alones?

Hi all! I'm burning a lot of DVD videos (I'm producing DVDs with content I've captured myself, vacation, parties etc) It's just one problem: Stuff is working GREAT with my DVD players, but my GF's players doesn't like it!

Here's the deal then.
I'm using a NEC ND-2500A for burning, and I'm using Verbatim discs with the MCC 003 code. Everything runs fine on my Philips 622 (old but reads everything) standalone DVD player, everything is working great with my Panasonic XV-10 as well. My brother is using the very same media for his PS2 with great success.

But when I put a disc I've burned into my girlfriends stand alone player, it won't read it. It's an old Thompson player, one of the first actually. Could be that, but they have a second player as well, that's just a year old. And it only play SOME (all discs are MCC 003) discs. Some times it reads them with success, some times it reads them with a gradient transparent black border rolling on the screen, from bottom to the top. And some times it doesn't read them at all.

Okey, so it doesn't like Verbatim? But why the heck does both the Thompson and the newer one at her house like som (in my eyes) crappy no-name DVD's?!

It's getting REALLY frustrating hearing the words: "Have you ever thought about that it may be YOUR stuff that's fooked up? And not everyone else?"

But since I'm using a great burner and some great discs, that's what I've snapped up here , it must be that my gf has some crappy players as well as my friend, since my brother doesn't have any problems with them on his PS2 and his stand alone dvd player that was VERY cheap.

And one more thing; I can't burn at 8x, well, actually I can, but the discs aren't readble! Shitty burner, or shitty discs? MCC 003 discs, and a NEC ND-2500A burner.

Any ideas of how I can check this stuff out?
May my burner be out of date or malfunctioning?
Should I change my media? (I don't like to since they are so easy to lay your hands on).

Thanks in advance, and I hope that someone can help me out with this issue since it's starting to get onto my nerves...

If you have used Nero then you have your answer.

Nero does produce not 100% comatible DVD Video dvds.