Whenever I change the Admin password, I cannot login as the Administrator anymore. I get only Administrator rights logged in under the default, that is user admin and password also admin??? Also when logged in under admin I cannot logout, it just keeps me logged in as admin???
It also doesn't work when I give a member Administrator rights, he will not be able to edit posts???
Have you been changing cookie-modes ? Because this sounds like a cookie problem. Try deleting all you cookies, make sure you've got cookies enabled in the browser and then try again.
I already thought it had to do with the Cookies and it did. Some cookies were written beside my own generated cookies and I had to find them and delete them.