Yesterday's OSX 10.6.2 roll out includes over a hundred fixes. Among them is a fix for a bug that users last month said was deleting their data when they logged in as a guest account. At the time, problem was said to affect users who signed into their computers using guest accounts that were enabled before they upgraded to Snow Leopard. RedOrbit reported that the bug had Snow Leopard recognizing the main account as a guest account, meaning that the profile was deleted when users logged out.
Aside from breaking Atom support for hackintoshes, yesterday's update also fixes this bug, which users first reported seeing nearly a month ago on October 13.