All these things I have done before on an identical previous installation on the same laptop, and it worked perfectly. So this is very confusing for me:
I installed Xubuntu 12.10 on my laptop and have now decided to install Gnome Shell (using sudo apt-get install gnome-shell) for when I want to show how pretty Linux can be to my Mac and Windows-using friends :D
Unfortunately, whilst Gnome now appears as a session on the login screen, loading it simply results in a blank desktop with no panel.
Is there a Gnome error log somewhere which I can access, or is there a common cause for this sort of problem? Thanks
EDIT - I tried switching to GDM as my display manager (using sudo dpkg-reconfigure gdm), and gnome-shell worked. But it broke again when I switched back to lightdm. This wasn't the case with my last installation - can anyone suggest what's gone wrong?