After a deluge of posts on Apple's MacBook support forum complaining of periodic or even total loss of keyboard function in MacBooks and MacBook Pros running Leopard, Apple has issued a patch for the OS.
According to users' comments, the glitch was reported to randomly cause keyboard input to cease until it "resolves itself," or until the user reboots. Trackpad function is reported to be unaffected, and in most instances, external keyboards appear to be safe from the malfunction.
Apple had originally dismissed this as a hardware issue, offering to replace keyboards and notebooks. But while the majority of complaints did come from users of "straight out of the box" Intel-based Macs, one user reported having the same problem after installing Leopard on a G4 PowerMac.
Users who had been running the earlier Tiger edition of Mac OS X for months with no problems, claimed the keyboard failure too after upgrading to Leopard, or in some cases during the act of installing the Leopard upgrade.
The MacBook Pro Software Update 1.1, available in the support section of Apple.com, should be the answer to this widespread bug. Leopard requires the 10.5.1 update before.