Multiple People Accessing Same File
 

I have a file that multiple people access and make changes to. When remote,
if a user has the file open, another user will not get a prompt telling them
the file is in use if they are trying to open the same file. When they are
done making changes and try to save the file, they get a message stating
changes were already made and those changes will be lost. This only happens
remotely. What can I do to correct this problem?

All users are using Office 2003 and Windows XP Pro.

Thanks in advance for your help.