Firefox consistently monopolises 99% of memory -- except, inexplicably, whenever I am on a Mozilla Support page. (I usually have three or four tabs open: hotmail, work email, Linkedin and theguardian newspaper. When I am 'on' any of these pages, Firefox usage is 94-99%; if I open a Mozill Support page, when I am 'on' this page, usage drops below 10%.)

I have tried all of the solutions suggested on the Support site (disabled all add-ons, run in Safe mode, re-installed latest version) but all to no avail. When left unattended for an hour or more, Firefox crashes, but is then "unable" to send a report. I use Windows XP.