Access database file reports file in use

A MS Access dayabase file being used by 2 users (never simultaneously) resides on a network share. The file now reports that it is in use by another user and can only be opened in read only. The file is not in use and each users workstation (NT4SP5 running MS Office 97) has been rebooted. I copied the file to my desktop and it still reports the same. I even took ownership of the file. I then installed Office 2000 and could open the file after converting it to a 2000 file, but now some of the tables do not function. I have tried all of the database rebuild tools in Access, and none work.