Is it possible more than one person has the XIN file open? If two sessions are opened, the first session to open the XIN gets read-write access and any subsequent sessions get read only until the initial session relinquishes the file. At that point. the next person to request read-write access will get it.
Also, the person with read-write access can relinquish read-write access from within the product and at that point, someone in the product can request read-write access.
All of this is done in the InRoads Explorer. Select the Preferences tab and on wither pane, right click on the name of the preference file. On the menu, it will show a check next to the active access. If you are in the session with read-write access, the checked item will be grayed out as it is not a valid menu choice. It you then select Read Only, these two items will switch. If you need to see who has read-write access, select Details and a little dialog bx will open showing all persons accessing the file.