Firefox 1.5.0.3 is a security update that is part of our ongoing program to provide a safe Internet experience for our customers. We recommend that all users upgrade to this latest version.
- Security fix for denial of service vulnerability.
Download: Firefox 1.5.0.3 (en-GB) | (en-US) | (Other Systems and Languages)
Hompage: Mozilla Firefox
Amarjeet Rai's Blog 
Backups shouldn’t be a hassle. A good backup plan will work forever