Thanks for support Error 500

Using WordPress 2.0.5
My link is this
http://odilian.com/conts/wp/

and I don’t know WHY I can’t add comments because I get the error there. I write a post but trying to comment on it is always error.
I used the previous wordpress version and it works without problems, but now I don’t know how to fix or what to do or why it happens.. Thanks yous! I couldn’t find something in the posts and trheads that’s why I’m posting hrere 🙂 sorry!