A Good possible reason is because you are 8 versions behind the current version of Firefox. Please update to Firefox 28 immediately [[Update Firefox to the latest version]] Also, if your computer supports it, consider update to Mac 10.9 as 10.7 is no longer secure.

If you still get these crashes after having updated then please post the IDs of one or more recent crash reports that have a "bp-" prefix if there are crash reports submitted: *bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx You can find the IDs of the submitted crash reports on the <i>about:crashes</i> page. *You can open the <b>about:crashes</b> page via the location bar, like you open a website, or open the crash reports page via "Help > Troubleshooting Information". See: *http://kb.mozillazine.org/Mozilla_Crash_Reporter *https://support.mozilla.org/kb/Mozilla+Crash+Reporter If you can't open Firefox, see: *http://kb.mozillazine.org/Mozilla_Crash_Reporter#Location_of_crash_reports *http://kb.mozillazine.org/Mozilla_Crash_Reporter#Viewing_crash_reports *https://developer.mozilla.org/How_to_get_a_stacktrace_for_a_bug_report