By Katie Marsal

Published: 09:05 PM EST

A simple technical note from Apple on Tuesday warns that it can't guarantee third-party devices like the Palm Pre will work with iTunes and adds that future updates to the software may break media syncing with third-party devices.

The document stresses Apple's belief in the tight integration of its portable devices with iTunes and clearly, if indirectly, signals that Palm's iTunes sync feature has no guarantees at all from the iPod maker.

"Apple designs the hardware and software to provide seamless integration of the iPhone and iPod with iTunes, the iTunes Store, and tens of thousands of apps on the App Store," the company says. "Apple is aware that some third-parties claim that their digital media players are able to sync with Apple software. However, Apple does not provide support for, or test for compatibility with, non-Apple digital media players."

Although it takes care to avoid implying that it will deliberately head off Palm's efforts, Apple also mentions that, since software "changes over time," future updates to iTunes may prevent sync with third-party devices from working at all with the jukebox app.

Whether or not this is likely to happen with the Pre is difficult to tell. The feature works by identifying the smartphone in its hardware ID as an iPod and would require that Apple detect the difference between the Pre and a genuine iPod. Many of Palm's current engineers -- as well as its new CEO Jon Rubinstein -- are former Apple employees who have worked on the iPhone or iPod and are familiar with iTunes' current methods of recognizing plugged-in devices.

The notice fires another shot across the bow of Palm, which Apple increasingly sees as a concern. Outside of belittling the number of apps on Palm's software store, the iPhone designer has previously warned that it will pursue patent theft if it believes anyone has copied its techniques -- although, again, Apple has made sure it doesn't directly accuse Palm of such an act.