One of our designers has a problem with modified links messages whenever he opens an In-Design file. In every file he opens, the links all show up as modified. If another user on the network opens the same file, the links show up as OK. Once he updates the file and saves it back, any other user that opens that file then shows the links as modified.
We have a dozen users, all Mac-based (10.6.8), all using CS5.5. We use a central Mac file server. Users copy a file to their desktop make corrections and then copy it back to the server. The server contains all the graphics linked within the file. The same problem arises when he opens a file directly off the server over the network, so it is not the physical location of the file. His file-sharing preferences on the server are the same as other users.
The only other issue (that we will be fixing soon) is that all the Macs, even though they are all synched to the Apple Americas/U.S. time server (time.apple.com), have different times on their computer (by a few minutes each way). While this has given us some problems in the past with people opening up the most recent file, but the date showing it was older, etc, this problem isn't happening with other Macs, whether they are set at a more recent time or older.
As a rule, yes, but in this case, it doesn't matter if the individual machines are off because whether they are timed before or after this one, they don't have the relink issue. Besides, some of the files are months (or years) old and they (or their path) have not been modified in that time.
We are working on getting a network synch to the main server, but it has been sketchy in the past.
I don't know a lot about Apple networking but you can connect via AFP or SMB, and in a couple of older versions of OS X you can also use FTP. I think if everyone is not using the same protocol it can cause waht you are seeing.