Reinstalling apache and recompiling php fixed it for some ppl on linux.
I had the same thing on my local host, but this did not happen on the production server. My local WAMP, LAMP products, all have the same version.
So for me, this works with them: CentOs 6.3, php 5.4, Apache 2.2.15
Btw, in my local, mb_detect_encoding () shows 'UTF-8', but the string is mess anyway.
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