The recommended way to change the audio from mono to stereo is to make movie in the WAV format. To do so:
1. Add the original audio (or original video that the audio) to the Timeline.
2. On the 'File' menu, click 'Make Movie'.
3. From 'Output Format', select the 'WAVE Format (Audio only)' option 4. Click 'Next'.
5. From the 'Channels' drop-down box, select 'Mono (Single)'.
6. Click 'Next' and proceed to make the movie.
The 'WAVE Format (Audio only)' make movie option is available only in the registered version of Video Edit Magic.
All the other formats also change audio properties internally depending on their specified properties.