Palm Zire 71 & syncing w/ 10.4

Are you synchronizing with the Palm Desktop, with iCal and the Address Book using iSync, or with iCal and the Address Book using the Missing Sync for Palm OS?

You're not likely doing anything wrong at all. You should, before proceeding, repair disk permissions with the Apple Disk Utility application, if you did not do so after, or have not done so since, installing the Mac OS X 10.4.8 update.

Then, launch iSync, open Preferences… and press the Reset Sync History button, and follow the directions which appear. Choose Merge—rather than Replace—when offered the option to do so. That process will leave your data intact, your sync clients registered, but force the framework to perform a slow, first-time synchronization, as if you had never synchronized before.

Before actually initiating the synchronization event, you should back up your iCal and Address Book records using the option to do shown under the File menu in each application.