Rather then something scary or confusing (black box) I would show something with positive connotations. A toolbox, a bandaid, a stethascope, etc.

Nice metaphor.

 
The icon should probably go with the message. If the message is “We’re Sorry”, the icon shouldn’t be “don’t worry, you’re safe”, as a life vest or parachute might imply. Since it’s a dialog box, likely to be glanced at for a few seconds and nothing more, uniformity between the icon and the message will ensure that those who don’t bother reading the message will still get the idea by looking at the icon. To that end, what’s the text in the dialog right now? Is it fairly uniform?

 
Semi-related, from an article on the Mac startup chime ( http://musicthing.blogspot.com/2005/05/tiny-music-makers-pt-4-mac-startup.html ):
>>”Mac people are very familiar with the sound, after restarting their machines too often. In fact, that was one of the issues I was conscious of when designing the sound. Turning the Mac on is one thing, but being forced to reboot from a crash is a totally different experience. I wanted to avoid a sound that would be associated with the crash. I wanted it to sound more like a “palette cleanser”.

 
How about jumper cables? Or jumper cables and a battery? Or a battery? Or a pair of AAs (which, of course, need to be regularly changed)? I like the idea of maintenance things. A screwdriver? Duct tape (please please please)? Soap? A toilet? A utility belt? Batman’s? The plumber’s? Batman’s?

Of course, none of these have to do with crash reporting, per se. Maybe a notepad? Or a clipboard? With some forms on it? Or a checklist with blank entries? Or something that resembles or evokes a survey? Or email or a telephone or Adiumy?

Maybe you could have an icon that denotes the RESULT of the crash report, so that the user is encouraged to click Send or whatever. Something that denotes a developer fixing the problem. A bug? A bug in a jar? In a net? Maybe something representing the problem in its fixed state. The bug under a boot? A Band-Aid?

My Dock has Disk Utility in it, and DU’s icon is a hard disk with a stethoscope. Maybe something along those lines—the diagnosis of the problem. It also has System Preferences, which entails gears. Maybe the icon could be showing Firefox’s “innards” (electronic or mechanical ones, not organic ones), as if to say “your thing just crashed because these two wires don’t connect”.

 
Lol: I typed this up hours ago and forgot to submit it and Keisuke Omi had a bunch of the same ideas as me and I’m too lazy to edit.

What’s the point of the crash reporter app? If it’s main purpose is to ease the pain/frustration of the application crashing then a focus on recovery sounds like a good direction… but it’s current name and functionality suggest that the point of the app is to collect useful data about the crash and report it back.

How about a bureaucratic-looking form clipped to a clipboard (too much overlap with copy/paste?) to communicate that the app documents the details about the crash and compiles it in a report. Maybe a magnifying glass (too much overlap with search?) or something medical like a stethoscope to put the emphasis on “diagnostics”.

In terms of working well when used by the other applications that are based on the Mozilla platform – Would doing something similar to the favicon for https://bugzilla.mozilla.org/ work? Displaying the icon of the Mozilla app that the crash reporter is associated with as a badge would communicate better which app crashed. This can be applied to the software updater too.

Overall I’m liking the ideas that focus on the recovery instead of the crash itself, like a parachute, life vest, or reload icon.