Charset problems

Hi, I'm using Kde with Suse 9.0 pro in English, my keyboard's layout is english also. My problem is with turkish caracters... I can't see them correctly, but this is not always true. For exemple in KMail, those caracters appear correctly in mails, but not in the mail list section, so I have two identical caracters in the same application, but one is correct, the other not. This is similar for Knode or Address Book also. I've looked for some global default encoding parameter in yast but i couldn't find out. Any idea? thanks