I have a strange 'clicking' sound exactly every second in a .mov file exported from AE 6.5.

I've exported the After Effects composition as a Quicktime movie, using the following audio settings:

Compressor: none
Rate: 44.100 kHz
Size: 16 bit
Use: Stereo

The original audio file is encoded as MPEG 3, Stereo, 44100Hz, 15.5Kbps

Does anyone out there have any ideas about what could be causing this?