hello, i am darkid from BBHeb.com - the official hebrew translation for MyBB.
i have just tried your Seo 1.0 System, and i have big problam, this is not work with hebrew letters.
in the url in change the hebrew letters to something like this :
%E1%E0%E2%E9%ED-%E5%FA%F7%EC%E5%FA-%E1%EE%F2%F8%EB%FA-f-23

you can check the problam here:
http://bbheb.com/forum/index.php

thanks for your help and sorry about the bad english.

In seo.php, find:

Replace with:

Let me know if that helps.