By Katie Marsal

Published: 10:05 AM EST

In a serious blow to Palm's fight to have its Pre smartphone sync with iTunes, the USB Implementers Forum has sided with Apple and chastised Palm for violating the forum's policies.

Palm initially petitioned the USB-IF in hopes that it would side with the handset maker in its efforts to have the Pre sync with Apple's iTunes music application, according to Digital Daily. But the group responded with a letter to both Palm and Apple this week, in which it said the Pre's alleged use of Apple's vendor ID violated its rules.

"Under the Policy, Palm may only use the single Vendor ID issued to Palm for Palm’s usage," the USB-IF letter states. "Usage of any other company’s Vendor ID is specifically precluded. Palm’s expressed intent to use Apple’s VID appears to violate the attached policy."

The letter also said that Apple's use of the vendor ID to limit iTunes syncing to proprietary hardware like the iPhone and iPod is within the rules of the USB-IF. It specifically said that Apple's actions are not "improper."

The USB-IF is a non-profit organization that supports the Universal Serial Bus and sets the standards for the hardware input. Unique vendor IDs are necessary for developing USB products.

Since the launch of the Palm Pre, the company and Apple have been engaged in a back-and-forth battle. When it first debuted, the Pre was able to sync with iTunes and transfer music from a user's library. Apple fired back and disabled the sync, only for Palm to respond. In the latest twist, the iTunes 9 update issued earlier this month again broke sync with the Palm Pre.

When contacted by Digital Daily, Palm said it is reviewing the USB-IF letter and intends to respond.

"We engaged with the USB-IF because we believe consumers should have freedom and choice in how and where they use the non-rights managed media they already own," Palm said.