I am running Ubuntu 2D 11.10. To enable shadowing I used gconf-editor and the GUI for 2D settings here: How do I configure Unity 2D?
Everything seems to run well; however, after restarting or log out, the shadow under the panel disappears. Shadows DO remain for windows, it is only the panel's shadow that disappears. To bring it back, using either gconf editor by unchecking and re-checking either compositing_manager or compositor_effects or 2D GUI settings does work, but unfortunately only for that session. Every subsequent restart/login requires to use either gconf or the GUI to bring the panel shadow back.
Any idea as to what may be causing the disappearance? I really like how the shadowing makes Ubuntu 2D look, but would rather not have to keep re-doing the process to enable shadowing for every session.
Thanks in advance!