In Firefox’s Help menu choose Check for Updates to download Firefox 3.0.1, a minor update that fixes Firefox 3′s most common causes of crashes. This update won’t cause any add-on incompatibilities
Last month a very serious vulnerability was discovered in the Firefox source code which affected both Firefox 3 and Firefox 2.x.x and could allow a hacker to execute commands remotely on a machine. Hopefully this new update will fix this Firefox security hole too.

Firefox 3.0.1 fixes a lot of bugs and security issues that spawned through the initial release of Firefox 3.0. A complete list of all such security issues can be found Here.
As it is the first update since Firefox 3, so it is recommended for users to upgrade to Firefox 3.0.1 immediately.
Raju PP is the founder-editor of Technically Personal, which is one of the most widely read technology blogs on the web. He holds an Engineering degree in Electronics & Communication, and has previously worked as a Technical Specialist in Banking Software domain.