As I was running out of space, I recently migrated my catalog and images to a Lacie Thunderbolt drive which is connected through an Apple Thunderbolt display. I have a recent Macbook pro.
Worked fine at first, then I began to get catalog error messages in LR4 and general messages about the disk not being ejected properly. It was sporadic at first, now happens every time I access the catalog.
I have tried restarting the computer and plugging the drive directly into the laptop. Same thing. I have Googled the topic but have not come up with anything useful.
It does not seem to be a LR issue to me, but I am curious that this only happened after I changed the catalog over to this drive which was previously my backup.