Thank you for your post.
It definitely sounds like the file reference was not released from the network, and I don't know of a quick way to access and release that information. As you discovered, rebooting the machine and disconnecting your machine from the network is not a solution.
Although using one copy of FileMaker Pro would be the ideal solution, is there a reason why you are running FileMaker Pro 7 and FileMaker Pro 9 on the same machine?
Thanks for the prompt response! I do not remember why IT kept FMP 7 on this machine (their logic is beyond me sometimes). I will take it up with them to have FMP 7 removed and see if 9 or even 10 will work for sharing. Thanks again!