Looks like you may be using XHTML. Try:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="content-type" content="application/xhtml+xml; charset=UTF-8" />
...
</head>
Or, for Latin 1 (English, Spanish, French, German, etc.):
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
...
<head>
Make sure the font family being used also has the characters you need to be displayed.
Also, see if browser encoding is set to utf-8 or iso-8859-1 with auto-detect off.
Take a look at "HTML codes to put German characters on your Web page".