strange charset problem with german/kyrillic chars

[trance202@xxxxxxxxx]

Hi Users

I use lots of month mutt, but one thing I can't solve. All Mails are in
the right charset (from russia, germany, etc...) in the pager. But, in
the index, if there are german umlauts or kyrillic chars, they are
displayed as '?'.

in my muttrc its this:
        set charset = 'utf-8'
        set assumed_charset = 'utf-8'
        set attach_charset = 'utf-8'

the console is konsole from kde on kubuntu 8.04:
        ~$ locale
        LANG=de_CH.UTF-8
        LC_CTYPE="de_CH.UTF-8"
        LC_NUMERIC="de_CH.UTF-8"
        LC_TIME="de_CH.UTF-8"
        LC_COLLATE="de_CH.UTF-8"
        LC_MONETARY="de_CH.UTF-8"
        LC_MESSAGES="de_CH.UTF-8"
        LC_PAPER="de_CH.UTF-8"
        LC_NAME="de_CH.UTF-8"
        LC_ADDRESS="de_CH.UTF-8"
        LC_TELEPHONE="de_CH.UTF-8"
        LC_MEASUREMENT="de_CH.UTF-8"
        LC_IDENTIFICATION="de_CH.UTF-8"
        LC_ALL=
and
        echo -n "ä" | wc -c
        2

If I write a message with öäü in the subject, then its displayed
correctly, but if someone write a message from russia with it, it is
displayed as strange '?'. Also the subject in the pager is not right,
but the message-body itself show the kyrillic chars correct in w3m.
The Message from there are in the header described as following:
Content-Type: text/html; charset=UTF-8
Content-transfer-encoding: base64

I don't know enough to debug exactly this problem, can anyone help me to
debug it and maybe find a way to solve it? 

Thank you for any help...
raphi