@ Robert , I have Nero 7 Ultimate installed on Vista 32 .
I tried a 3 video compilation & didn't have a audio problem.
I guess it is possible I did the process differently.
Could you give a more detailed description of your process ?
If it is different I will give it a try & see if I have a problem.
I usually don't use Nero for this type compilation.
I prefer AVStoDVD with DVDFlick as my second choice;
The video I ended up with only has one menu selection for all 3 videos .
The other programs have a menu selection for each.