DAE Errorrs

[columbiaaudiosuite]

I keep experiencing a couple DAE errors when I try playback. I get DAE -9131 or DAE -9060. My project is on a firewire drive on a LE system. If I move the file to the internal hard drive it works, or if I go to a HD system it works off both firewire or hard drive.
But why do I get the errors in the first place? I have MANY projects on firewire drives and cannot keep copying them to the internal hard drive every time. And I don't have enough HD systems to work on them all. How do I fix the LE system to play off of a firewire drive?

Specs:
PT 8.0.3
Mac OS 10.5.8