Piwik + varnish

Hi,
I have some problems configuring my local piwik app.
I use a dedicated server with varnish installed. when I install piwik, I cant log in to my username. it says: Error: Form security failed

I have added the following lines to my config.ini.php
General]
proxy_client_headers[] = "HTTP_X_FORWARDED_FOR"
proxy_host_headers[] = “HTTP_X_FORWARDED_HOST”

could someone please provide me with a solution? I really need piwik installed.