By Aidan Malley

Published: 04:15 PM EST

While Apple markets MobileMe primarily as a push service, some are now discovering that updates to the Mac don't translate to immediate updates for the web or for Apple's handhelds, raising questions about whether the new service is as full-featured as promised.

As illustrated in an official knowledge base article and supported by reports from Mac Rumors users, instantaneous data sync only occurs whenever a change is made from either the MobileMe web interface or a portable device such as the iPhone or iPod touch.

Even with Mac OS X 10.5.4 and a MobileMe update, however, Mac users just won't see the same level of speed when they make changes from the computer itself. The automatic option for sending data from the Mac is now known to be inherently tied to the operating system's Sync Services, which don't relay information except at regular 15-minute intervals -- a potential hassle for users expecting content to automatically spread within moments to all their computers and devices.

And while it's simple to override the automatic schedule with a manual sync, the absence of full computer-based push has quickly been labeled a disappointment to some users and reveals that Apple has yet to completely integrate push information with Mac OS X.

Mac OS X Snow Leopard is believed to solve the issue for business customers with built-in Exchange support but isn't yet known to have a new sync model that would deliver the updates in real time.