I start Cheese on my 12.04 installation. I have used it before in my previous installations but since I upgraded to 12.04, no joy! I have a GeForce GT-520 video card with the "recommended" additional proprietary drivers installed and activated.
I tried to run Cheese from the terminal and got the following errors:
dozens of these errors:
(cheese:5467): Gtk-WARNING **: Theme parsing error: gnome-applications-light.css:42:23: Not using units is deprecated. Assuming 'px'.
about a dozen of these errors:
(cheese:5467): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkToggleButton, but as a GtkBin subclass a GtkToggleButton can only contain one widget at a time; it already contains a widget of type GtkLabel
only one of these errors:
(cheese:5467): CRITICAL **: cheese_camera_device_get_uuid: assertion CHEESE_IS_CAMERA_DEVICE (device)' failed Segmentation fault (core dumped)