Why does GNOME panel open up when I launch UNITY 2D instead of Unity panel? This I am starting to see from last 2 days, any idea how to fix this?
What's likely happening is that
gnome-panel is set to run on login, and as such it'll automatically start every time you log into GNOME. So, what you can do is to open up Startup Application Preferences (AKA
gnome-session-properties), and check for something that has a you don't know what it is, then you want "Edit" that item, and see what comes up.
Keep going through the list until you find the
gnome-panel command tucked away somewhere.