In situations where WaveBurner has to bounce a project before burning a disc (such as when using fades or effects), it may only write the table of contents to the disc. The resulting disc contains no audio data.
This happens if you set WaveBurner to use outputs other than 1-2 on your audio hardware. To resolve this issue immediately, open WaveBurner preferences, click the Audio Driver tab, and choose 1-2 from the Output pop-up menu.
To prevent the issue in the future, update to WaveBurner 1.1.1 or later. You can download the update from Apple Downloads.