Problem with Polish characters in "From:"

Hello.

I've got problem with Polish characters in From: header.
Is there any way to fix it ?

In archives my header looks like this :
From: fenio(_at_)o2(_dot_)pl (Bartosz Fe<weird sign>
where "weird sign" is something like black rhombus.
It should looks like this :
From: fenio(_at_)o2(_dot_)pl (Bartosz Feński)

Can I fix it ?

regards
fEnIo

-- 
      _          Bartosz Feński aka fEnIo | tlen/mailto:fenio(_at_)o2(_dot_)pl
    _|_|_     32-050 Skawina - Głowackiego 3/15 - w. małopolskie - Polska
    (0 0)      phone:+48501608340 | ICQ:46704720 | GG:726362 | IRC:fEnIo
ooO--(_)--Ooo  http://skawina.eu.org | JID:fenio(_at_)jabber(_dot_)org | 
RLU:172001

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