User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/20100101 Firefox/18.0 Build ID: 20130104151925 Steps to reproduce: This problem started just after upgrading to version 18 of Firefox desktop. The browser closed completely (and pops up a crash report window) when I close a tab (usually the right most one but sometimes other tabs), when I close a second browser window, and at other times as well. Actual results: Browser closes when it shouldn't and pops up a crash report window. Expected results: Should have stayed open and allowed me to continue surfing internet.

Yes this was a duplicate of 831101. See my comment at end for resolution.