Mac glitch wiping hard drives

A problem is causing some of those who install the new version of Mac OS X to lose the data that's stored on their external hard drives.

Apple Computer said the glitch is limited to external hard drives that use a high-speed FireWire connection and a particular chipset Oxford Semiconductor manufactures. The company encouraged those who have a drive that uses the chip to disconnect their drives from Macs that are being upgraded to Mac OS X version 10.3, or Panther.

"Apple has identified an issue with external FireWire hard drives using the Oxford 922 bridge chipset with firmware version 1.02 that can result in the loss of data stored on the disk drive," the company said in a statement. "Apple is working with Oxford Semiconductor and affected drive manufacturers to resolve this issue, which resides in the Oxford 922 chipset." An Oxford Semiconductor representative declined to comment.

Apple recommended that customers do not use drives that have the Oxford chip in question. "To stop using the drive, you should unmount or eject the disk drive before doing anything else," the company said.

Among the drives that are affected are the d2 series of FireWire 800 drives from LaCie. The company said the affected products have serial numbers less than "1339xxxxx" or "0339xxxxx". The drives shipped between April and the end of September.

"LaCie has been actively investigating these reports to identify the cause of the problems and to provide our customers with a solution," the company said in a statement.

LaCie added that it was able to test beta versions of Panther and did not experience the problem. Panther, the latest version of Mac OS X, went on sale Friday. The new operating system adds more than 150 new features, including improvements on its Finder and mail programs, among other enhancements.

Ina Fried writes for CNET News.com