Really looks like some character set 'mess-up'
First: we need to be sure if it woked OM with a previsous version. Which version do you think worked? Do you still have the installer?
Second: It is important here to know if it is MySQL version 4.0 or 4.1. Execute “select version()” to find out! Wiht tell the exact version!
Third: Let us see the returns of ” show variables like '%character%' “
I think you mean SQLyog 5.13.
(if not I would like to know from where you got 5.31 🙂 )
Please try latest 5.17 RC too!