37signals fixed the issues with the Backpack API and PackRat will work now. No update is required. However, you’re data file might be corrupted. Just delete your data file and resync and you should be good to go.
No data should have been lost because you should only be having problems if you synced with the new Backpack. This means your changes were sent up to Backpack before you downloaded the bad data.
If you’re having problems please send an email. We’ll get you going again.