I'm trying to get SSI to work on Debian running Apache, however the .shtml files are not being parsed. From a PHP file with phpinfo() I can see that the following show up in the loaded modules section:

mod_mime_xattr mod_mime mod_mime_magic

In /etc/apache2/mods-enabled/mime.conf I have (among other things):

AddType text/html .shtml
AddOutputFilter INCLUDES .shtml

In /etc/apache2/sites-enabled/domain.com.conf (for the virtual host in question) I have:

<Directory /home/username/public_html>
Options +Includes
allow from all
AllowOverride All 
</Directory>

and for good measure, I added the following as well:

<Directory />
Options +Includes
</directory>

In the user's .htaccess file, I tried adding:

Options +Includes
AddType text/html shtml
AddHandler server-parsed shtml

Nothing seems to work. How can I even debug this?

Edit:

Here is the output of ls /etc/apache2/mods-enabled/ in case this helps

actions.conf          dav_svn.load         proxy_balancer.load
actions.load          deflate.conf         proxy.conf
alias.conf            deflate.load         proxy_connect.load
alias.load            dir.conf             proxy_http.load
auth_basic.load       dir.load             proxy.load
auth_digest.load      env.load             python.load
authn_file.load       fcgid.conf           reqtimeout.conf
authz_default.load    fcgid.load           reqtimeout.load
authz_groupfile.load  mime.conf            rewrite.load
authz_host.load       mime.load            ruby.load
authz_user.load       mime_magic.conf      setenvif.conf
autoindex.conf        mime_magic.load      setenvif.load
autoindex.load        mime-xattr.load      ssl.conf
cgi.load              negotiation.conf     ssl.load
dav_fs.conf           negotiation.load     status.conf
dav_fs.load           php5.conf            status.load
dav.load              php5.load            suexec.load
dav_svn.conf          proxy_balancer.conf