Soundtrack Pro - Can't export to AIFF

I'm diving into Soundtrack Pro for the first time, and am hitting a roadblock when I try to export to an AIFF file.

The project is just one track, using some filters and processes to clean some noise. I select the Export menu, Exported Items is set to "Master Mix" and I select "AIFF" for the File Type. However, the file exports with an "AIF" (minus an "F) extension. I've tried showing the extension, hiding the extension, manually typing "AIFF" instead if "AIF" in the file name, but it still exports with and "AIF" extension and doesn't seem to be playable.

To preview the exported file "AIF" file, I try to open it in iTunes, but it refuses to open. If I export to an "MP3" file, it works as expected. What am I missing??