Yes if you add an audio track that's longer. The default track is only 30 seconds long.
One thing to watch out for is if the playing time of the media in the project is close to the 120 minute limit adding longer music to the menus can push it over the limit and prevent encoding and burning.
The tracks I added are all a couple of minutes so that shouldn't be the issue.
Also, I don't know if this relates to my question, but I'm using a double layer dics to include more media and do not have a 120 minute limit.
Follow this workflow to help ensure the best quality final product:
Once you have the project as you want it save it as a disk image via the File ➙ Save as Disk Image menu option. This will separate the encoding process from the burn process.
To check the encoding mount the disk image and launch DVD Player and play it. If it plays OK with DVD Player the encoding was good.
Then burn to disk with Disk Utility or Toast at the slowest speed available (2x-4x) to assure the best burn quality. Always use top quality media: Verbatim, Maxell or Taiyo Yuden DVD-R are the most recommended in these forums.