Mark/Space today announced the release of The Missing Sync 5.1 for Palm OS is now available. This release provides native support for both Intel and PowerPC Macs, providing the best performance possible on either processor. Version 5.1 also improves syncing with Tiger’s Address Book and iCal data, adds backup options and is better at handling calendar events assigned to specific time zones. The Missing Sync is priced at US$39.95 ($24.95 upgrade from version 4.0 or earlier).