Error while archiving folder in Outlook 2003 ... already exists

[The4B's]

Lately when Outlook 2003 does the auto archiving I get an error message for
one folder that reads:

Error while archiving folder "folder name" in store "store name". A folder
by this name already exists.

I don't know what to make of this message. The folder name exists in both
the store and the archive. It only happens with this one folder.

I'm running Outlook 2003 SP3 on Windows XP Pro SP3.

Thanks.