Try replacing the MP3 audio files on the timeline with WAV files.
When you create a DVD the video and audio is rendered to MPEG-2 video and Linear PCM Audio.
WAV Audio is Linear PCM format.
Carl312: Windows 10 64-bit 8 GB RAM,AMD Phenom II X4 965 3.4 GHz,ATI Radeon HD 5770 1GB,240GB SSD,two 1TB HDs.