First, I've got to say good job of being able to use 58 machines at the same time. You must be tired clicking away on all of them, watching for Firefox crashes. (Do you think that maybe, just maybe, it doesn't get back to you every time Firefox crashes? Just maybe?)
I'm using all windows XP with the latest updates. Dell desktop and Fujitsu laptop at home. No-name brand at work. The crashing problem is getting better but it still crashes more than IE. Never had a crash with Opera.
Not only would they tell me about a Firefox crash. they call me for such things as their mouse pointer running off the screen (and can't find it), putting a CD in upside down (& why won't it work that way), etc.
Keep in mind that most of the users a news reporters. That should explain a lot, especially if you've ever been around them much. Never have problems with accounting or graphic arts and they have more sophisticated machines.
In the Weather Dept. (my main job) we have a mini-net of 8 machines....nary a problem there.
If anyone could crash anything, it's news reporters.