When you replace a Palm device, you should reset the Sync Services framework to insure that a first-time slow synchronization takes place. Under these conditions, it's best to select the option to replace the information on your Palm device with the information from iCal and the Address Book, and not to merge such data.
To do that, you launch iSync, open the Preferences… dialog, press the Reset Sync History… button, and follow the directions which appear.
Before replacing a device, you should elect to back up your critical iCal and Address Book information, using the option to do so under the File menu of each application. In the case of catastrophic data loss such as you experienced, you can then very quickly restore you data to iCal and the Address Book, and overwrite your Palm device with it.
The Palm Desktop has virtually nothing to do with this process once you've installed and activated iSync and the iSync Palm Conduit, except that the HotSync Manager and Transport Monitor provided by Palm must be present and active to launch, supervise and end a synchronization session.
The Palm Desktop, however, can serve as a repository of outdated contact and calendaring data, and may provide a means by which to replace some of that information. It cannot export your to do or task data, however, in a form which can be imported into iCal, so that data is not available to restore in the manner described below.
To restore contact records, simply launch the Palm Desktop, select the Address List view, then the Export… option under the File menu. Name your export file, and be sure that these values are selected:
Module: Addresses
Items: All nnn Addresses
Format: vCard
Be sure that Export all columns is selected, or use the Column… button to select a subset of them to limited the data exported, and press the Export button.
You can perform essentially the same process to export calendaring events as a vCal file, but—again—you cannot do so for task data.
