Forums Bug Reports [6.17] multibyte display option reversed

Chinese Simplified
[130451] -NickServ- 6密码正确，感谢您的使用。
is display as
6密码正确，感谢您的使用。
when both "multibyte display" and "utf-8 display" is turned on.
but ok if either one turned off

(ie make Chinese character into 密 due to the encoding of this forum)
(use javascript:'密...' to show origin text if u want)