The 10.4.3 Update delivers overall improved reliability and compatibility for Mac OS X v10.4 and is recommended for all users.

It includes fixes for:

– AFP, SMB/CIFS, NFS and FTP network file services
– AirPort and Bluetooth wireless access
– Core Graphics, Core Audio, Core Image, and RAW camera support
– disc recording when creating and burning media
– .Mac sync services
– Spotlight indexing and searching
– Dashboard widgets: Dictionary, Flight Tracker, Stickies, and Unit Converter
– Address Book, AppleScript, Automator, Dictionary, Font Book, iCal, iSync, Mail, and Safari applications
– Disk Utility, Keychain Access, Migration Assistant, and Software Update
– compatibility with third party applications and devices
– previous standalone security updates

For detailed information on this Update, please visit this website

For detailed information on Security Updates, please visit this website

I’m hoping this will fix my wake-from-sleep keyboard failure problem.

UPDATE:
Unbelievably, I can’t reproduce the wake-from-sleep keyboard problem since the upgrade – it looks like the upgrade fixed it! Wohoo!