My project stores html code fragments for use in templating in files with a custom extension (*.phtml). I find that Visual Studio is inconsistent in its use of editors when I edit these files. Sometimes it provides no intellisense, sometimes it treats the files as XML (which is better than nothing), and sometimes I get lucky and it provides me with the HTML editor.
I've configured Visual Studio to treat *.phtml files as HTML, but that doesn't seem to make any difference.
What more can I do to convince Visual Studio to always use the HTML Editor for *.phtml files?