[Mediawiki-l] Special Pages gone after 1.8 upgrade

[Scott M]

After upgrading from 1.7 to 1.8.1, my wiki no longer has any special pages.
I can't even login now because the UserLogin special page is missing.

I just get a page that says: 
There is currently no text in this page, you can search for this page title in other pages or edit this page.

RecentChanges, RandomPage, etc all return the same thing.

But all the user added wiki content is working fine.

Any ideas?

 -Scott