I was having six tabs open, one is an online pdf and two are from Google Images while the rest are forum tabs. The Firefox (ver 19 which I'm using currently) lags whenever I search for images using Google and in seemingly random occurrence, it will cause the Firefox to immediately crash with no warning. I had lost a significant portion of my time in composing emails and searching for information due to this unexpected error and it had occurred for past three versions of Firefox for me, pointing at the same initial triggers, having Google Images tab open. Checking the crash reporter reveals nothing as it stated "EMPTY: no crashing thread identified; corrupt dump." I hope the Mozilla team would immediately rectify this problem as it's quite annoying--and time wasting.