How to export presentation with a song/audio

Hi. My presentation is completely automatic. No manual clicks required. All slides automatically flow with transitions.

I added music (an MP3 song) to these slides. In Keynote, it plays fine. The song plays when the slides are moving.

But when I export it as a MOV file to Quicktime, it creates TWO separate files:

1. Myfile.mov

2. Myfile-soundtrack.mov

Just playing Myfile.mov does not help, it does not have sound. What nonsense is this? Is this Apple's famous UI design?

Anyway, how do I merge these files? Some googling suggested I use GarageBand. So I paid 19 bucks for this software, but even Sending to GarageBand does nothing, it just creates a .MOV file that still does not have sound.

Any ideas or pointers?

I have Quicktime Player on my machine (although like any sane person, use VLC for any video playback) and also have the iWork 09 and GarageBand latest. My OS is Mountain Lion latest..

Thanks.