[Zope] Zope.org search bug -- can't search for "book"

I'm getting a System Unavailable message when I do a Zope.org search for the keyword "book". However, a search for anything else, i.e. "bookworm", works fine. Any ideas? SiteIndex ! System Unavailable This site is currently experiencing technical difficulties. Please contact the site administrator for more information. For additional technical information, please refer to the HTML source for this page. Thank you for your patience. Error type: KeyError Error value: 3711 - T.J.