Unable to update public free/busy data

[Stephanie]

Last week I set up offline folders, trying to put a local
copy of my Outlook Calendar on my computer. That didn't
solve my real problem, so I turned off offline folders and
deleted the associated .ost file.

Now, whenever someone sends me a meeting notice and I
accept it, it does not show up in my calendar. A few
minutes later I get the message:

"Unable to update public free/busy data. Operation failed."

When I look at the meeting acceptance email in my Sent
mailbox, it says that the meeting has been moved or
deleted off my calendar.

Does anyone know what's going on? I've tried the Knowledge
Base, to no avail.

Thanks,
Stephanie