Hi,
how do you set the Permissions on your Folders? Did you set Share Permissions for "Everyone" Read and then handle the Directory Permissions via NTFS Permissions?
I had the same Problem a few Months ago, the Share Permission on the Share Root Folder was set for Everyone and then i catch the directory permissions with NTFS. From V5 to 6 EV changed his behaivor in interpreteting Windows Permissions. But there is a Registry Key you can set to force EV to use the NTFS Rights. If you set this Key the Users should see only the Archives for what they have permissions in the File System.
If you have this Problem, let me know and i will search my Documents for the Key.