[Plugin: WP Super Cache] Full error message. (replaced my website url with example.com)

You don’t have permission to access /wp-content/cache/supercache/www.example.com//index.html.gz on this server]

this plugin was working, i upgraded to wordpress 3.4. i’m not entirely sure if it’s caused this problem.

http://wordpress.org/extend/plugins/wp-super-cache/