Is this in any way related to the freezing problems on the new Alu iMacs?
About Hard Drive Update 1.0
The Hard Drive Update 1.0 includes bug fixes and important updates for the following systems:
iMac Core 2 Duo (Mac OS X 10.4.7 or later)
Mac Pro (Mac OS X 10.4.7 or later)
To complete the firmware update process, please follow the instructions in the updater application (/Applications/Utilities/Hard Drive Update 1.0.app). The updater will launch automatically when the Installer closes.
http://www.apple.com/support/downloads/harddriveupdate10.html
About Hard Drive Update 1.0
The Hard Drive Update 1.0 includes bug fixes and important updates for the following systems:
iMac Core 2 Duo (Mac OS X 10.4.7 or later)
Mac Pro (Mac OS X 10.4.7 or later)
To complete the firmware update process, please follow the instructions in the updater application (/Applications/Utilities/Hard Drive Update 1.0.app). The updater will launch automatically when the Installer closes.
http://www.apple.com/support/downloads/harddriveupdate10.html