Mark / Space has updated Missing Sync for Palm to version 5.1, with native support for Intel Macs, improves syncing with Address and iCal data, new backup options and improves handling of calendar events assigned to specific time zones. You can read the details here.
Missing Sync 5.1 is a free upgrade for registered users of version 5.0, but note that you should perform a final synch with the current version before upgrading. You should also, as a precaution, backup your computer and your Palm data, before upgrading. There’s a helpful Mark / Space article on creating backups here.