Logic Pro 9 8 bit mystery


I loaded a small project I hadn't touched for some months. Used to work fine in LP9. Now some of the audio files won't load as they are in 8 bit format. Don't know how they got there or why they worked and now don't. I won't be heart broken if I can't save as it was only a few measures of fill. However, I am curious as to why this occurred. This was electric guitar plugged into an Apogee interface. Audio that was miked (also plugged into the Apogee) recorded as 24 bit.

Any insight into this would be most helpful. Thanks, Larry