Because of this it is probable to have two cookies (even session cookies) in the jar, one keyed as a symbol, one as a string. These two cookies are sent to the browser and the browser "chooses" which cookie to use. If it is a session cookie (as was my case) things like csrf get reset on every request which makes submitting forms hard.
fixing sym and string cookie name, two cookies to browser bug.
Looks good, tests please?