The SSI servlet of Tomcat always sends its output as UTF-8 even if the outputEncoding and inputEncoding variables for this servlet are set to another encoding (for ex. iso-8859-9) It does not matter if the variables mentioned above are set, or the page has a character encoding set for itself, output is always UTF-8.
Yep, UTF-8 was hard-coded. The fix for this is in 5.5.10+ *** This bug has been marked as a duplicate of 10385 ***