On some installations of Wordpress, all updates performed through the administrative web interface require the FTP username and password to be entered before they take place. Others update and install themes/plugins just fine without needing FTP information. I'd like to test some permissions hunches by forcing the web administrative interface to update via FTP. Is this possible?
(Note: Certainly using a regular FTP client would work, but I'd like to keep the client away from as many additional steps and applications as possible. Keeping them to the web interface would make life... simpler.)