Comment 10 for bug 721142

Right, I can see how it's confusing, we turn apport off by default in stable distribution because reporting bugs is not what stable users should have to deal with and we get most of the common issues reported during the unstable cycle or by technical users so that will take care of the issue for you.

The dialog which is confusing you is apport's way to tell you that a crash file is available which you didn't report yet without locking your keyboard asking for your admin password to be able to access it, it let you decide to report the bug or delay that to later. One reason you might see it often is because you do guest session testing and any crash in those session would trigger that dialog, the dialog will also be displayed every time a new issue is detected, that can be frequent in unstable cycle. You can turn apport off if you don't report those issues anyway and want to get ride of the dialog.