[Plugin: WP Super Cache] directly cache file

And a second message displayed by supercache :

“Directly Cached Files

Warning! /homepages/20/d309396555/htdocs/ericburlet.com/ is writable. Please make it readonly after your page is generated as this is a security risk.”

I just don’t know wich file is it about and where to find it in my blog directory. Anyone can help?

Thank you

Eric