Make sure the character set is explicit on the server.
utf-8 is the standard and most used:
AddDefaultCharset utf-8 AddCharset utf-8 .html .css .js .xml .json .rss .atom
Make sure audio/video works by defining the MIME type on the server:
AddType video/ogg .ogv AddType video/mp4 .mp4 AddType video/webm .webm