Yep your tip work. I'll check Turkish translation tomorrow and send here if correction needed. You can write my mail somewhere in case you need update Turkish translation in the future, thanks for everything.
In user comments section Turkish characters have no problem. But the popup messages and my messages on top of the page such as your nick (İsminiz) Turkish characters like İşıçö has problem how to correct this? I added Turkish words to english.php and added $SCRIPT_ENCODAGE = "windows-1254"...