Here's how you can disable system crash reports in Ubuntu 13.04.
1. Open a terminal window.
2. Type in the following command then hit Enter.
sudo gedit /etc/default/apport
3. Change the last line from "enabled=1" to "enabled=0"
4. Save the file and close it.
5. Enter this command to shut down the currently running crash report service. sudo service apport stop
For more, see the original article at the link below.