已经安装3.0的用户可以直接点菜单的Help->Check for Updates自动安装
安装后的：
What’s New in Firefox 3.0.1
Firefox 3.0.1 fixed several issues found in Firefox 3.
* Fixed several security issues.
* Fixed several stability issues.
* Fixed an issue where the phishing and malware database did not update on first launch.
* Under certain circumstances, Firefox 3.0 did not properly save the SSL certificate exceptions list.
* Updated the internal Public Suffix list.
* In certain cases, installing Firefox 2 in the same directory in which Firefox 3 has been installed resulted in Firefox 2 being unstable. This issue was fixed as part of Firefox 2.0.0.15.
* Fixed an issue where, when printing a selected region of content from the middle of a page, some of the output was missing (bug 433373).
* Fixed a Linux issues where, for users on a PPP connection (dialup or DSL) Firefox always started in “Offline” mode (bug 424626).
http://www.mozilla.com/en-US/firefox/3.0.1/releasenotes/
http://download.mozilla.org/?product=firefox-3.0.1&os=win&lang=en-US
我用的插件里面，Tab Mix Plus和Function for keyconfig不兼容3.01，不过到他们各自的网站下载最新的dev build就能解决，链接如下：
tmp:
http://mark.bockenstedt.net/wp-content/uploads/2008/07/tab_mix_plus-dev-build.xpi
