Apple has posted MacBook, MacBook Pro Software Update 1.1. It's available for download from the Apple downloads Web site.
The update "addresses a responsiveness issue on MacBook and MacBook Pro notebook computers," according to Apple. Apple noted that some MacBooks and MacBook Pros may occasionally experience a suspension of keyboard input which can last a minute or longer.
Mac OS X v10.5.1 or later is required before the software update can be installed.