You might have to reload the page before it shows you as logged in (old bug). Also make sure you didn't click Logout on any of them, or it will delete your autologin token. Login/logout will be global later on anyway.
If it just isn't working at all, well, that's what this topic is about. Any old autologin cookies might conflict with the new ones if you don't delete them.
Mobile browsers, for some reason, don't want to implement ContentEditable. There's a feature request open for it but it's a big job and not high priority. It's easier to just have mobile users unable to post for now rather than trying to lecture
them on using HTML.
For anyone still caring, there is one or two mobiles browsers that'll get the job done, though I forget which now. I removed them because I didn't like the GUI or something.