http://hain.jp/index.php/tech-j/2007/02/13/p125
設定の肝だけ抜粋
;; Disable Output Buffering
output_buffering = Off
;; Set HTTP header charset
; default_charset = EUC-JP
;; Set default language to Japanese
mbstring.language = Japanese
;; HTTP input encoding translation is enabled.
mbstring.encoding_translation = off
;; Set HTTP input encoding conversion to auto
mbstring.http_input = pass
;; Convert HTTP output to EUC-JP
mbstring.http_output = pass
;; Set internal encoding to EUC-JP
mbstring.internal_encoding = EUC-JP
;; Do not print invalid characters
mbstring.substitute_character = none
mbstring.detect_order = SJIS,EUC-JP,JIS,UTF-8,ASCII