Apple has released a Bluetooth Firmware updater for its Wireless Keyboard and Mouse.
Version 1.0.2 provides updated firmware for DLink USB Adapters revision B2 or later, and Apple Bluetooth internal modules on PowerBooks and PowerMacs.
Apple claims the firmware update: improves connectivity between the computer and the Apple Wireless Keyboard and Mouse; improves the update-installation process; enables better performance when waking the computer from sleep; and supports additional key commands during startup.
The updater is not supported by any other Bluetooth modules and Apple warns that "using this firmware update will make your Bluetooth module incompatible with Windows based systems".
Apple also caution PowerBook users to update the firmware only when plugged into an AC adaptor.
The updater requires Mac OS X 10.2.6 or later, a Apple Internal Bluetooth module or a D-Link USB Bluetooth Adapter (DBT-120, rev. B2 or later), and OS X Bluetooth 1.3 client software.
Further information and the 2MB download are available here.