Bug lurks in Mac OS

Apple Computer (AAPL) is enjoying brisk sales of the newest version of its Mac OS, but the success has not been without a few glitches.

Both in the U.S. and internationally, a limited number of Macintosh computers have been affected by a problem that occurs after users install Mac OS 8. The bug prevents the computer from restarting and in some cases erases information from a user's hard drive.

Reports have surfaced in Japan, the second-largest market Macintosh market in the world, that some users have been affected by this problem.

Certain models in the Power Macintosh 6300, the Performa 5400 series sold to education customers, and the Performa 6400 series and 6500 series, as well as the 20th Anniversary Mac, are among the affected models, according to a special Web site the company set up.

"Apple has become aware of a problem with some 5400/6400 or 5500/6500 series computers which may be triggered by the installation of Mac OS 8. After a shutdown, some users are reporting that the computer starts up with a blinking '?' mark, and they are unable to restore their hard drive," according to the company's Web site.

Earlier this week, Apple began offering software to fix the system. In Japan, Apple will distribute the fix for Japanese language computers on October 15, according to a report in Japan's Nihon Keizai Shimbun.

Of several tens of thousands of Mac OS 8-based models sold in Japan, only several hundred may be defective, an official with Apple Japan, the U.S. company's Japan subsidiary, told Nikkei.

Around three percent of the affected model numbers sold in the U.S. may exhibit the problem, according to an Apple spokesperson.

Apple says that in the meanwhile, users should choose the "Sleep" command rather than the "Shut Down" command because problems only occur after users choose to completely shut down the system.

The fix will be added to new copies of Mac OS 8, and added to new PowerMac boxes immediately. Customers can receive the fix on CD by calling Apple's technical support line or from their order center.

Mac OS 8 was released in late July in the U.S. and has sold several million copies so far. The software is number two on list of top selling CD-ROM's for August, according to market research firm PC Data.