Using Varnish in a Symfony Application?

Question

My goal is to use Varnish to cache my static assets with my Symfony 1.4 site (http://my.perqworks.com).

I can write a VCL file that strips out cookies on all static files while leaving the user authentication cookie on the php file -- but the user authentication is failing. I cannot log into my application.

I am looking for an answer that describes how to use Varnish to cache static files while allowing my Symfony application to log in and support user authentication.

Currently I am using something like this:

if (req.url ~ "\.(png|gif|jpg|swf|css|js)$") { unset req.http.cookie; }