Why does Firefox printing suck so much?

Seriously. It’s crap. And I have no idea why! Does anyone have an explanation? Opera and IE manage relatively well… and Safari, being an Apple app, would probably perform in a manner typical of that company’s products in the print field, but Firefox screws up margins, text spacing, links, and all manner of other things. It’s just broken!

I’ve had problems with Windows versions of Firefox as well, so don’t try and tell me it’s just Linux (though that may be a part of it). Any ideas/links to Bugzilla?