[eluser]Alex007[/eluser]
I don't get it, not using baseurl() isn't supposed to automatically add a PHPSESSID to every link in your pages.
I don't use baseurl() at all (but my CI install it at the root of my htdocs) and I definitly don't have weird PHPSESSID appended to my urls...
It reall sounds like a config thing on your webserver. IIRC, PHP can be configured to append the session ID afetr ALL urls ()when cookies are not present), this is probably what's happening. Now why does it go away when you add baseurl() is even stranger.