You are far from the first Mozilla employee that has responded to my complaints about Firefox, but you are the only one thus far that has been civil. In fact, just a few days ago, I was trolled on twitter by a Mozilla employee over my responses here.
Sorry to hear about the trollery. I'm looking into it.
I wonder if you have a profile that goes back years and has some property that tickles a latent bug. Sorry if I missed it: have you tried running on a brand new profile? You'll have to use the -ProfileManager option on the command line at startup, I think.