It's the same on our wiki too... except in Mediawiki:sitenotice. Try putting {{NAMESPACE}} in Mediawiki:sitenotice (which is what the poster wanted), then viewing pages in different namespaces, and you'll see what I mean. It's always "MediaWiki".
DanB
-----Original Message----- From: Zak Greant (Foo Associates) Are you sure that {{NAMESPACE}} behaves this way? Both on my local install and on mediawiki.org, {{NAMESPACE}} is empty on pages that are in the default namespace.