If you are running a previous version of Mac OS X 10.4.x (Tiger), you may receive the message ‘.Mac Sync Client is out of date.’ More …
Some .Mac improvements will cause reduced functionality for prior versions of Mac OS X. For example, Mac Sync will no longer support syncing calendars between a Mac OS X 10.3.x-based Mac and a Mac OS X 10.4.x-based Mac. More …