Apple has released the latest version of the iTunes 8.2.1 software, which prevents owners of Palm's Pre phone from using Apple's downloading service. According to Apple, iTunes 8.2.1 "provides a number of important bug fixes and addresses an issue with verification of Apple devices."

However, the new version also prevents the software from working on Palm ?s new Pre smart phone. The update disables devices such as the Pre from connecting to the iTunes software.

Apple?s move to block such devices may hurt the appeal of the touch-screen Pre among music fans. Palm, which released the Pre last month to challenge the iPhone, said shutting out access to rival devices will only harm Apple customers who rely on iTunes to manage their digital music collection.

Pre users can continue to access iTunes through earlier versions of the software, or by transferring songs from an external drive. In addition, there are third-party applications available online that synchronize iTunes playlists, music, and podcasts with a mobile device.