Comment 21 for bug 578585

I can confirm this behaviour on a Samsung NC10.

Deleting ~/.config/gnome-session/saved-session has an effect, the same flashing background occurs but the Ubuntu log in sound plays before entering the cycle.

Running "mutter --replace", all is well but if I then run unity, or issue "Running mutter --mutter-plugins=/usr/lib/mutter/plugins/libunity-mutter.so.0 --replace" I get:

(unity:4943): Gdk-WARNING **: /build/buildd/gtk+2.0-2.20.1/gdk/x11/gdkdrawable-x11.c:942 drawable is not a native X11 window
The program 'unity' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
  (Details: serial 516 error_code 3 request_code 20 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)