Almost as quickly and quietly as it appeared, the “nVIDIA Update 2009″ package posted earlier this week has disappeared from Apple’s web site and Software Update servers. Despite initial reports from readers that were very positive, since then many have reported experiencing as many if not more problems after the update than they did prior to installing it.

From the release notes originally included with the update, the changes were stated to include:

About NVIDIA Graphics Update 2009

This update improves cursor movement when using the Apple Mini DisplayPort to Dual-Link DVI adapter with the Mini DisplayPort enabled MacBook Air, MacBook and MacBook Pro.

It also improves playback of HD video running on systems with NVIDIA GeForce 7300 GT or GeForce 9600M graphics.

Thus far, Apple has pulled the page where the update/release notes were posted and has made no public statements as to the reason(s) why the update has been redacted.

Customers have been more active on this topic than nearly any other in Apple’s Support Forums, where many have reported serious issues with screens blanking out, instability (crashes & visual display-image corruption) and flickering behaviors that can affect things as “small” as the mouse pointer/cursor, or the entire screen(!).

We will continue to track these reports closely and provide updates on the situation as they become available.