Both SMF and Website using UTF-8 - Why this error?

[Sakae]

My Wordpress 2.9.1 uses UTF-8 (just check the code on my website http://www.daletigre.com) and my SMF 2.0 RC 2 also uses UTF-8 (check it http://www.tigrelog.com.br).

So why when I install a widget using SSI, I get this error? (printscreen attached)

I'm not sure what's happening, is it something about the widgets on WP?

Thanks in advance.