Today's update to iTunes (8.2.1) prevents owners of the Palm Pre from syching their phone with Apple's media software.
An Apple spokesman told The Register: "iTunes 8.2.1 is a free software update that provides a number of important bug fixes. It also disables devices falsely pretending to be iPods, including the Palm Pre."
The Palm Pre had previously been able to synch directly with iTunes, transferring (non-DRM) music bought from the iTunes Store, as well as users' photos.
It's a typically protectionist move from Cupertino but one that Jobs might live to regret. Apple already enjoys a near-monopoly position in the supply of digital music, and anti-trust regulators - particularly in Europe - might relish the prospect of taking on Apple after big wins against Microsoft and Intel.
Pre users can still load music on to their phone using the USB, or simply not upgrade iTunes to the latest version. There are also numerous third-party apps that allow (at least for the moment) the Pre to synch with iTunes.
The Palm Pre will launch in the UK exclusively on the O2 network, "in time" for Christmas.