Old thread, but I have to add my +1 to "Entire Mix" not actually meaning "Entire Mix". I see the other options people mention and eventually found them, but it was a frustrating road that killed creativity until the next day.
Also, when the documentation for the Export Audio dialog says "If you select any data in your project, only that data is included when you choose to export audio", it would be helpful to point out that there's a
Select,
None item in the
Edit menu. Because simply making sure that you don't have a track selected isn't enough. Try this: select one audio track, then click it again to de-select it, then try the
File,
Export,
Audio menu item -- you'll get an error dialog saying there's no audio in the select track, which is also not intuitive.
Chris