I’ve been having the same error, and it is very annoying. Suzanne, are you also on an Intel Mac? I wonder if that is where the problem occurs, because my co-workers do not have the same problem, but they are on PowerPC G5’s.
As a workaround, I’ve had luck taking the audio into Quicktime and exporting as a QT movie, with sound only. That seems to import fine, although its a pain in the tuccus.