If you’re yet to upgrade your Firefox browser to version 3.0, read this carefully because phishing is a serious issue.

Mozilla is removing the anti-phishing feature starting version 2.0.0.19 of Firefox. The reason being given is that Google, which provides the phishing data via the SafeBrowsing protocol, has asked Mozilla to disable the feature in Firefox 2.0 since it relies on an obsolete version of the protocol.
The best approach is to upgrade to Firefox 3.0 but if you still insist on using Firefox 2.0, consider getting third-party tools like the Netcraft toolbar, Web of Trust or Firephish that add phishing protection to your Firefox 2.