From http://www.apple.com/support/downloads/macosxupdate1047ppc.html:

– The 10.4.7 Update is recommended for all users and includes general operating system fixes, as well as specific fixes for the following applications and technologies.
It includes fixes for:
– preventing AFP deadlocks and dropped connections
– saving Adobe and Quark documents to AFP mounted volumes
– Bluetooth file transfers, pairing and connecting to a Bluetooth mouse, and syncing to mobile phones
– audio playback in QuickTime, iTunes, Final Cut Pro, and Soundtrack Pro applications
– ensuring icons are spaced correctly when viewed on desktop
– determining the space required to burn folders
– iChat audio and video connectivity, creating chat rooms when using AIM
– importing files into Keynote 3
– PDF workflows when using iCal and iPhoto
– reliable use of Automator actions within workflows
– importing and removing fonts in Font Book
– syncing addresses, bookmarks, calendar events and files to .Mac
– compatibility with third party applications and devices
– previous standalone security updates

Time to upgrade!