japanese headers getting corrupted

[Ramprasad]

I have cyrus-imapd-2.2.3 on FC1 


When mail is delivered from postfix to cyrus , via unix lmtp some mails
with japanese characters in headers ( from: and Subject: ) get changed

The headers get replaced with "XXXXXX"   ( non-ascii chars become X )  
but the body is not changed at all 

something like this 
Reply-To: "XXXc  X^XX" <concurring503 at chan.ne.jp>
From: "XXXc  X^XX" <concurring503 at chan.ne.jp>
To: <feedback at voxtab.com>
Subject: XXXXXXXXXX


Do I have to do any setting to allow japanese characters ?


Thanks
Ram