>Not sure this helps you but I have just found several other successful transactions of opening this file - imediately before, during and after these two people were having problems gaining access.

The problem I'n referring to ONLY pertains to the SAME user trying to re-open a file they have previously opened. Anyone else can come along and open it (once, at least) fine. The server caches file info when it opens a file/table, such as file name, path, user, connection, time opened, how long open, etc. You will have to check the server directly to analyze this with a tool like Server Manager.

This is one thing to look for: When a problem-user attempts to open the table and has trouble, immediately completely close the local app, and check the server to see if the user has the table listed as "open." If the user is listed on the server with the file open, check the data on the table (how long open, etc), and take note of it. Give it a couple minutes and a few refreshes to close, there is often a slight delay. Then, if the connection is still open, you may have found your problem. The server should terminate unused file caching after a short time - if not, that's a likely problem.

At this point, close the user's link(s) to any open app-related files on the server (or with server tool), and try opening again by running app from the local machine, see if it works correctly.

Pick one bad user and see if there's a pattern with the server not terminating the server-cached files properly. This trouble can be caused by hardware problems or clock desynchronization, two suspects, at least. Also, certain caching methods on certain OS can be related to this.

The above method may help identify the problem, but may not, also, if it's a local user-side hardware problem, for example - just something to look at. What kind of network and machines are these, BTW?