Here is the solution from sonic support.
If anyone having this troubble.
Hello Pelle,
Go to the layout editor and make sure that you set the disk info in the properties to unchanged 30 character type files, and not one of the 8.3 types. Set the layer break after you have included the rom content so it gets counted in.
Mux the project to a Video TS, do your eDVD authoring, set the output file types to 30 character and then point ot the eDVD files as rom content, Then set your layer break. Then write a disk image and DLT.