Apache ignoring mime-type

Apache ignoring mime-type

I have a page that is using JWPlayer to serve a video in a variety of
format choices (mp4, m4v, ogv, webm). However, when accessing the page
from Firefox (23.0.1) or with PHP curl, Apache is returning a header
indicating the content-type as text/plain. Firefox (and newer IE versions,
unless in compatibility mode) will not play the video. I have tried adding
the mime types in mime.types, httpd.conf, and in an .htaccess file in the
directory.
mime.types
video/mp4 mp4 m4v
video/ogg ogv
video/webm webm
httpd.conf
AddType video/mp4 mp4 m4v
AddType video/ogg ogv
AddType video/webm webm
.htaccess
AddType video/mp4 mp4 m4v
AddType video/ogg ogv
AddType video/webm webm
I have tried with and without the dot in front of the extensions (which as
I understand should work either way). I have restarted Apache. I have
verified that I am editing the right configuration files. Still Apache
continues to return the text/plain type. Where have I gone wrong?