I like to think I keep up-to-date with what's happening with Firefox but it seems a security update slipped out the door on the 24th without my noticing it. Version 1.0.2 fixes three vulnerabilities, including one that, as the saying goes, allows the execution of arbitrary code (geek speak for anyone can run anything on your PC). Note carefully that the install instructions say to remove your previous version of Firefox before installing this one.
There is also an update to the Thunderbird e-mail program so you may want to update that too. Release Notes are here.
Aloha!