Okay, so until recently I was recording on GarageBand 1, using a Digidesign 002 rack, which was working perfectly fine. I upgraded to iLife '06 today, and when I opened GarageBand 3, I got the error message, "Error code 28773 was returned by the CoreAudio driver". I plugged my guitar directly into the 002 rack to record a test track (to make sure everything was working fine), and I got no signal. Throughout this entire process, I continued to get the same error message, and I have no idea what it means.
Also, out of all the programs that came with iLife '06, GB3 runs excruciatingly slow, and frequently freezes.