I've done several DVD projects with NeroVision and always delete the project when done. However, the pictures and audio files I imported for menu background remain in the list of background pictures/audio. It's getting cluttered with stuff I no longer want but can't figure out how to get them out of there.
There still there because they are still in the folder you browsed to for them. If you do like I do and put the pix and audio that are going to be used in a unique folder I made you can then just delete the files and they no longer show up.