File server management - Read+Write but 0 Locks

[Christine L]

Any one knows why in Windows Server 2003's File Server Management Console, some "Open File"'s "Open Mode" is "Read+Write" but "# Locks" can be 0? If It is Open as "Read+Write", at least 1 x lock exists... Some of my users complaint some of their Excel files on network drive can be open by others directly (without prompt for "Read Only") while He/She opened that file already. And those excel files are not set as "Share Workbook"...