After syncing footage in CS5 with external audio, where do I store it?

Hi,

I'm a photographer new to editing.

I've moved my footage to the timeline, unlinked it the video/audio, synced the audio from an external recorder to the video, the linked those two.

I then moved the footage into a new bin the the project window. When I then move that footage back to the timeline, the footage has the original audio that I deleted, and the new audio is gone.

Any ideas? Where should I be moving the footage with the synced audio to store it prior to starting the editing?

thanks,

Chuck