I've just upgraded to Natty, having patiently waited for the final release date and for Ubuntu to nag me about it every minute. Now, whenever I log into anything other than Ubuntu Safe Mode, the system hangs. The mouse doesn't work, the clock freezes, the ssh connexion is broken. This happens AFTER THE LOGIN, on ALL desktops, except for safe mode, including Unity, Classic and, my standard desktop, KDE.
I can't find any error in any log. All seems to work fine. Sometimes the system starts for a couple of seconds and then freezes, sometimes it freezes while the desktop is still loading. But the computer is completely unusable outside of the safe mode.
I'm thinking, if there is a list somewhere of what Safe Mode does NOT start, I could start all of these things one by one and see what makes my system freeze that way. Is there such a list somewhere?
Or even better: does anyone have an idea of what it might be? The problem does not come from the 3D or Compiz or anything of the kind. That works. I've tried it and disabled it from KDE. Plus, "Classic no effects" has the same problem as the rest.
What could it be? And what does Classic Safe Mode not do?