Apple just released the he 10.4.6 update that is recommended for all users and includes general operating system fixes, as well as specific fixes for the following applications and technologies:

• login and authentication in a variety of network environments
• file access and byte range locking with AFP file sharing
• network access when using proxy server automatic configuration files
• connecting to Cisco VPN servers using IP/Sec
• using Bluetooth wireless devices
• searching iWork and Microsoft Office documents with Spotlight
• saving Word documents automatically when using a network home directory
• creating Automator workflows for iPhoto 6
• synchronizing contacts and calendars to .Mac and mobile phones
• mounting and unmounting iDisk volumes
• compatibility with third party applications and devices
• previous standalone security updates.