Outlook: Folder sharing is not available

We have a user that wishes to share his contact list with other employees in his office.
Everyone receives email via the same Exchange 2007 server.

He did the Permissions for the contacts (Right click, permissions added the user) and when she selects “SHARE CONTACT” she gets the error
“Folder sharing is not available with the following entries because of permission settings on your network.”

Possible Solution

If your user in cached mode? If yes, try to do a Send and Receive, if that fails, disable cached mode, restart outlook, try to share the contact again and then re-enable the cached mode.

Cache Mode Toggle in Outlook 2007:
Tools > Account Settings > Highlight your Exchange server account, and then click Change
To turn Cached Exchange Mode on or off, under “Microsoft Exchange Server:”, check or uncheck Cached Exchange Mode. Click Next, and in the window that opens, click OK.
Click Finish. Restart Outlook for the change to take effect.