It's becoming something of a turn-based strategy game, the way Palm and Apple are fratching over iTunes.

With the semi-major iTune 9 upgrade, Apple once again took the option off Palm Pre users for syncing their device with its media library software, which Palm had originally snuck into its code in time for its smartphone rebirth.

PreCentral has been following the process employed by Palm in order to make the Pre compatible with iTunes, since the WebOS 1.2.1 has apparently re-enabled compatibility.

It seems this compatibility was originally achieved by the Pre duping iTunes into thinking it was an iPod. When Palm put a stop to that, WebOS got it going again by setting its USB vendor ID to mimic Apple's.

The iTunes Cold War has now been stepped up once again as the latest WebOS version apparently now tells iTunes the Pre is manufactured by Apple and offers a product ID identical to an iPod Video - once again allowing the Pre to sync.

Which means it's now Apple's turn to make a move. Presumably Palm will eventually run out of serial numbers and IDs it can use to fool iTunes, but for the time being, iTunes 9 and WebOS 1.2.1 are compatible.