The Mozilla organization has released a new version, 3.5.1, of the Firefox browser today. According to the Release Notes, this version fixes some stability issues, as well as a problem specific to Windows systems, that led to long start-up times. It also fixes some security issues; unfortunately, the link to the list of fixed issues is broken at the moment. (I’ll update this post to identify the fixes as soon as I can get to the page.)
You should be able to get the new version via the built-in update system (under Help / Check for Updates). You can download versions for all languages and platforms here.
Update, Thursday, July 16, 23:15
The Security Advisories page has now been updated, and it appears that the JIT bug that I wrote about a couple of days ago has been fixed. Well done to the Mozilla folks for their quick response.