When you use iSight or a USB microphone to record audio in GarageBand 2, you may get recordings that sound too high pitched and play back too fast.
This issue only occurs on Mac mini computers. GarageBand only supports audio interfaces that operate at 44.1 kHz. The iSight only operates at 48 kHz. On most Macintosh computers, you can't select iSight as an audio input source in GarageBand—the choice will appear dimmed with the words, "not 44.1."
Because the Mac mini has no built-in audio input source, if you connect an iSight to it and open GarageBand, GarageBand will automatically default to selecting the device, even though the iSight selection will still remain dimmed and say "not 44.1."
When you record form iSight and then play it back, your 48 kHz file gets played back at 44.1 kHz, causing the speed and pitch discrepancy. To record audio on a Mac mini, you should use an audio interface that supports 44.1 kHz operation.
This document will be updated as more information becomes available.