Apple has released a couple of firmware updates for the system management controller (SMC) in the 2007-2008 MacBook and MacBook Pro systems. These are the systems that were available before the aluminum "unibody" systems were released.
The update addresses problems that prevented the systems from charging with the newer power adaptors with the "L-shaped" magsafe connector.
The downloads are about 880KB in size, and should be available through Software Update for relevant systems, but can also be downloaded from the following Web pages.
The update will require OS X 10.5.8, or OS X 10.6.4 or later, and will require a restart to install. Be sure you have your system fully backed up (manually invoke Time Machine if you use that, or create a fresh drive clone) before installing the update.
To prevent a possible power outage during the firmware update, which may render the system useless, the updater will require you to either have your battery installed and charged to at least 25 percent or have the power adapter connected.
When you install the update and reboot, you initially will see a gray screen with a progress bar on it, and during this time the system's fans may blow at full speed. This is because the system management controller is offline and cannot govern fan speed to control the system temperatures, so to prevent potential overheating the controller turns the fans at their highest speed.