If you use a Custom Label as the value for the "title" attribute of Apex Page, it does not render a title at all for the page's code.
per the documentation, the title attribute should said the page title, with exception to "developer mode". i presume "developer mode" is the browser-based deverloper tools that you can set in personal preferences. i don't use that at all, and can confirm that this title attribute is not working in my dev org, and my prod org, in both regular VF and via Sites as well.
