"Error 406: Not Acceptable" ?

[Ronnie]

If you?re seeing a lot of ?Error 406: Not Acceptable? errors on your site, or when publishing to the server using Microsoft FrontPage, it?s most likely the result of something triggering a rule in the server's "mod_security" rules. AWH uses mod_security to block hijack attempts and known attacks against the server, but sometimes it gets triggered by mistake. This can happen if something on your site (like a URL) matches a string we filter on, or if FrontPage does something that accidentally flags a mod_security rule during publishing.

A quick way to resolve this is to put the following in a .htaccess file in your web site's /home/username/public_html directory:

SecFilterEngine Off

This will disable mod_security for your domain.

More about what .htaccess files are an how to use them can be found here and here.