Apple update fixes issues with some Nvidia cards
(Macworld.com)
Apple / Mac News
Macworld.com - Apple on Monday afternoon released Nvidia Graphics Update 2009, which according to the release notes is designed to improve cursor movement (reducing jumpy or erratic movement) when using Apple's $99 Mini DisplayPort to Dual-Link DVI Adapter with the latest MacBook Air, MacBook, or MacBook Pro.
Source: Yahoo! News: Apple/Macintosh News