I install version 4.0.x(0-2) in Ubuntu 12.04 x86.
I can not show presentation mode but I used to show presentation with version 3.6.x in same machine. So I guess this problem depends on new version.
I got the following error when I show presentation.
(soffice:3584): Gdk-CRITICAL **: IA__gdk_screen_get_monitor_geometry: assertion `monitor_num < screen_x11->n_monitors' failed
(soffice:3584): Gtk-CRITICAL **: IA__gtk_window_resize: assertion `width > 0' failed
I found a work around which I set X windows display 1024x768 because
my setting for display is 1680x1050. So it is not good solution for me.
Thanks for reporting!
*** This bug has been marked as a duplicate of bug 62815 ***