Yep, tried that. Disabling hardware acceleration makes no difference.....
FWIW, after having had the multiple crashes, and reverting to Firefox 23, I tried going to www.filehippo.com and downloading the full version of Firefox 24 and overinstalling, rather than updating through the Firefox Help / About tab, in the browser.
Been running Firefox 24 for several hours, and no crashes 
Update, per my previous post. Now been running a fresh install of Firefox 24 for two days, and no crashes. 
That's great news!
I hope it stays that way for you.
Thanks for letting us know.
Hi Dave, no problem. Fwiw, after I Live Updated Norton and rebooted just for the hell of it, I downloaded the full version of Firefox 24, and with the overinstall it seems that Mozilla and Norton are now playing well together, and no squabbles !....