Apr 16 2005
According to the notes provide by Apple:
The 10.3.9 Update delivers overall improved compatibility and reliability for Mac OS X v10.3 “Panther” and is recommended for all users.
- file sharing and directory services reliability for mixed Mac and PC networks
- Mail, Safari and Stickies application reliability
- compatibility for third party applications and devices
- previous standalone security updates
More information on specific fixes is available from the link provided above.