error message

[Scott]

Good Morning,
A person reported to me this morning that when trying to access my site on manilasites.com, they received the following message:

"Sorry! There was an error: The attribute "allowDirectoryListings" must be true.
The error was detected by Frontier 7.0.1 in mainResponder.respond.
Webmaster: webmaster@userland.com. Time: Fri, 08 Feb 2002 18:30:07 GMT. "

What would cause this message?

Others have had no problem getting in during the same time frame.
Thanks
Scott