I'm using premiere pro CS5.5 with Macbook pro and a LaCie hard drive. Just opened my drive and my hour long movie project is entirely offline. The timeline shows "all media loaded" but every clip, still, song etc. is "offline" All my media is on the same drive where it has always been. Have not moved anything anywhere. I can play any of my assets on this drive individually, nothing is lost or missplaced. Ideas?
I am a PC-only guy, so much of this will not apply directly to the Mac, but perhaps with a bit of "reading between the lines," it might be helpful.
On a PC, the OS assigns drive letters (I think that the term on the Mac is "volume name"), and depending on how/when an external is plugged in, the drive letter might differ. The links to Assets in PrPro are absolute Paths, so every aspect must always match, including the driver letter, or name. On a PC, one would just assign a permanent drive letter to an external, so, regardless of the order that the external is plugged in, and regardless of what else might be plugged in, the OS sees that external as the exact same. Hence the absolute Path remains the same, and linked.
I am certain that a Mac-user will be along momentarily, and will help you pick out Mac-specific details, and offer instructions on making sure that the Path is the exact same for your LaCie external.