The most likely source of this problem is an extension. From your extensions list, Thirty Day Challenge Toolbar is the most likely one to be causing this. Try disabling this, then restart Firefox.

If it still happens, try disabling the remaining extensions - see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

Thank you! I didn't sign up for that toolbar. They put it on without me knowing. I uninstalled it, so maybe this will help.

Nope, that evidently wasn't it. Now it's jumping on any site where I'm typing into a box. FB is the worst. The 30 day challenge is the only change I've made, and it's now gone. I think I'd rather have the crashing.