The 10.4.1 Update delivers overall improved reliability for Mac OS X v10.4 and is recommended for all users. It includes improvements for:
– File sharing using AFP and SMB/CIFS network file services
– Using DHCP in wireless networks
– User login when accessing LDAP and Active Directory servers
– Core graphics including updated ATI and NVIDIA graphics drivers
– Synchronization with .Mac
– Address Book, iCal, Font Book, Mail, and Preview applications
– Widgets: Address Book, Flight Tracker, Phone Book, and World Clock
– Creating and burning disk images using Disk Utility
– Compatibility with third party applications and devices
For detailed information on this Update, please visit this website: https://www.info.apple.com/kbnum/n301517