Why would an old profile cause it to be scanned hundreds of thousands of times? (Yeah, I'm resetting it next time just in case... 10 years is amateur's numbers :) )
Anyway, there are a lot of people reporting the same thing on the internet. I've found 3 different bugs opened for the same thing.
But yeah, as far as I remember, Iceweasel doesn't do it either. Maybe I should change my browser.