It's because the burner don't like the discs or the combination of write speed and discs.
If you have burned the same discs at 2.4x before and that worked, it could be that laser head needs a cleaning with a cleaning disc. Another possibility is that the burner is broken.
4x write is also supported with that media, so that could be worth a try.
Have you tried to burn another image?
You can use Notepad to see the layer break value in E:\XXXX\XXXX\XXXXXXXXXXX\XXXXXXXXXXXXXXXXXXXXXXXXXXXX\XXXX.dvd if there should be something odd there.
I have burned 25 of the same discs at 2,4x which works perfectly and I have tried different images, but I also know theres nothing wrong with the images I try to burn.
No problems with layer break as you properly have guessed its a X360 game, and I have always set the layer break under the write options.
With all the things I have been trying to resolve the problem and that it came out of nowhere, I believe there's a problem with the Verbatims disc or the burner. But then again its 2 different 10 pack bundles and I got no problems before, so its properly the superdrive.