[SOLVED] Unity doesn't start properly

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http://ubuntuforums.org – Hello, I'm running 12.04 with Unity on my computer. And, for some reason, Unity now doesn't start as it should when you boot the computer; the windows don't have a menu bar at the top of them (the decoration is missing) and the Unity launcher doesn't appear (after logging in, the desktop icons appear but flicker for a second or so and nothing else happens.) Launching a terminal from a keyboard shortcut and typing "setsid unity" causes unity to re-load and all is fine from then on, but when you log out and in, the same problem occurs again. (I guess you could re-start unity by pre (Hardware)