http://www.mozilla.org/en-US/firefox/18.0.2/releasenotes/
There are several unresolved issues and a huge list of Bug Fixes including JavaScript related stability issues: http://www.mozilla.org/en-US/firefox/18.0.2/releasenotes/buglist.html
18.0.2 added a check to Options > Privacy > Accept third-party cookies, which I preferred to uncheck.
If you do not receive an update notice when using the application, select “Check for Updates” from the Help menu.
Or download:http://www.mozilla.org/en-US/firefox/all/
