"We are aware of the issue, which occurs only in extremely rare cases, and we are working on a fix," an Apple representative said in a prepared statement Monday.
It's the first time Apple has said it is looking into the issue. In early September, a handful of Mac users reported the issue on Apple's discussion boards. The problem, when it occurs, goes like this, according to ZDnet's sister site CNET's MacFixit: when logging into the guest account on their Mac first and then logging into their regular account, some users are finding all their data to be missing and their accounts completely reset.
It doesn't appear to be a widespread problem--there are less than 100 posts on several current discussion threads on the issue--but it's certainly topical. Microsoft is currently dealing with a massive data loss at its Danger subsidiary, the company it acquired that makes the Sidekick mobile phone.
Apple's data loss issue is also yet another problem related to its most recent operating-system release. Snow Leopard has been plagued with bugs since its release, including problems with the Finder hanging or crashing, incompatibility with certain apps, and the AirPort connection dropping.