Mozilla doesn't understand hyphens?

Just got an email from Neophytos saying that something was wrong with my site rendering on Mozilla, so I checked it out. Turns out it was this very long word, that confused Mozilla:

“everything-and-the-kitchen-sink- but-you-have-to-pay-extra-for-everything- and-you-can’t-even-do-simple-things”

I posted this word a couple days ago, and it turns out that Mozilla won’t use the hyphens or dashes to wrap the word across multiple lines. (I’ve inserted a couple spaces now, so it’ll work with Mozilla.)

Is this a bug in Gecko (which, supposedly, handles everything so correctly that none of the billions of pages out there display quite right), or is that the way it’s supposed to? Is there some HTML entity you can use instead of a normal dash, to tell Gecko that it’s okay to wrap the word here?