Seeing "embed" makes me think you've selected the wrong file type again.
I can't think of a reason why moving the file from one computer to another, or using a file that was linked when on another computer would make any difference. As far as ID is concerned the link is either up-to-date, modified, or missing, and that's based entirely on the path information and timestamp in the pointer that is the link. Are these files stored on a network, maybe? A bad time synch with the server might be an issue (and would cause all the links to show as modified even if they haven't been, as I would guess is the case with most of the images).
You mentioned if I perused the forum I'd find ohter refences to this problem, but my search has turned up only this thread. Do you have some other links?