Well, easy to solve for non-japaneses
find /usr/share/squirremail/functions/mime.php
if (!$charset_converted) {... <<< line 316
...
} <<< line 323
and do this (comment it out)
/*
if (!$charset_converted) {... <<< line 316
...
} <<< line 323
*/
Dont know if we run in trouble if we get a japanese charset in a mail but
I think the worst case is som char_scramble in the mail view.
greez willi