hello pameadow, could you provide your latest few submitted crash reports? please enter about:crashes into the location bar, copy the latest few report ids from there starting with bp- & paste them here into a forum reply. this will give us a better understanding what may be triggering those crashes.

bp-d69a04b4-857d-48ba-e404f2150224. that's the latest crash report. do you need others?

this crash report is missing a few characters and isn't valid unfortunately, so please recheck it. and yes, if you could add the latest couple of them also this could be helpful as well. thank you!

sorry. bp-d69a04b4-857d-48ba-93d5-e404f2150224.

4A21430E-77E4-4A50-A488-8BD7853A1298 5D464728-F376-48C1-898F-C7BB2BA17544

as you can see, the last two don't have bp at the start.

can you try updating to firefox 36 which just got released and see if the issue is reproducible there: Update Firefox to the latest release

also, do you use any plugin or external software on your computer that might be interacting with or changing the behaviour of facebook?

I updated for Firefox 36 and the problem has disappeared. Thank goodness. Many thanks.