Comment by ahockley on Latest version of Wordpress 2.9.2 issues 404 host headers by default. How to prevent this? - http://stackoverflow.com/questio...
This just seems like a bad idea. If the page is gone, the proper thing is to return a 404 header. Sure, users will benefit from something friendlier, but 404 is the proper header. If the page was moved or such, you should setup proper redirection (likely 301 or 302).
- Aaron B. Hockley