All that we needed to add was the following few lines in the httpd.conf file:
# Enable WML (Wireless Markup Language)
AddType text/vnd.wap.wml .wml
AddType image/vnd.wap.wbmp .wbmp
AddType application/vnd.wap.wmlc .wmlc
AddType text/vnd.wap.wmlscript .wmls
AddType application/vnd.wap.wmlscriptc .wmlsc
DirectoryIndex index.wml