Calendar sharing

I've followed all the instructions about Calendar sharing
in Outlook 2000 using Net Folders and yesterday when I set
it up, it worked great. This morning when the users
receiving the calendar updates booted-up they received
this e-mail and now nothing shows up in the shared
calendar:

The "user name's Calendar" Net Folder administered by
user name, has changed stores. All items in this Net
Folder must be reloaded from the Net Folder
Administrator. This will take some time, please be
patient.

What would have caused this? Who is the Net Folder
Administrator? Will the users eventually see all the
shared info? So far, it's been a couple hours and nothing
is showing up.

Thanks,

Tom