Dokuwiki could restrict the cookie to it's path (eg. /dokuwiki).
I guess the last method would be the correct way to handle this. Could yo u file a feature request?
Can you please explain me how I have to make a feature request?? (I need to be logged in, and I have to be albe to log out sometimes...)
Just visit http://bugs.splitbrain.org (optionally create an account and login) and choose "New Task". Change the type to "feature request", fill out the fields and add a description of the feature you want to have implemented.