How do I prevent QuickTime from creating 2 audio files (24bit and 32bit) when exporting to GarageBand?

When I am using QT to create an audio file, it is creating a 24bit and 32bit version. Which should I use with Garage Band, and how can I stop QT from creating 2 files each time?

[Re-Titled by Moderator]

Original Title: Quicktime creating 2 files