Apple's latest update to its Mac OS operating system offers more than three dozen fixes for bugs ranging from unprompted data deletion to spontaneous system logouts. And to the consternation of some Apple fans, it also disables netbooks hacked to run the OS on Intel's Atom processor.

Apple released the OS X 10.6.2 "Snow Leopard" update Monday.

The list of bugs the update fixes includes an issue that caused data to be deleted when users logged in as a guest, a glitch that causes unexpected system logouts, and a bug that compromises the duration and reliability of VPN connections.

Also fixed are issues with font spacing, brightness settings, improperly formatted E-mails from Exchange servers, Mobile Me syncing, and about three dozen other problems that affected the previous version of Snow Leopard. It also includes a number of security updates.

Mac OS X 10.6.2 is meant to "enhance the stability, compatibility, and security of your Mac," Apple said. But the biggest change that the update foists upon host computers may also be the least popular.

According to numerous user reports, it breaks support for so-called "Hackintoshes"—Intel Atom-based netbooks that have been modified to run Snow Leopard instead of their original operating system.

Netbooks are becoming increasingly popular with computer users willing to trade horsepower for portability and convenience.

Apple obliquely warned users that installing OS X 10.6.2 could wreak havoc on systems that employ unauthorized modifications. "You may experience unexpected results if you have third-party system software modifications installed, or if you've modified the operating system through other means," Apple warned.

That's not sitting well with some Mac users, who've long complained about the monolithic control Apple maintains over modifications to its products, including the iPhone. "I think it should be up to the customer what hardware they want to install even if it's not supported by Apple," wrote a user on a forum maintained by the tech blog TG Daily.

Others, however, weren't as concerned about the issue. "I don't see that as a big deal—Apple is trying to protect its investment. Hackers will always find workarounds for such problems," wrote a poster named Daniel.

Apple has not formally commented on the policy.

Mac users also have experienced problems with previous Snow Leopard updates, including a glitch known as the spinning wheel of death.

InformationWeek Analytics outlines the 10 questions you need to ask to see where netbooks fit within your organization. Download the report here (registration required).