SQL Azure Data Sync Preview is not backward compatable with the CTP2 version.
This article covers how to move from the CTP2 version of SQL Azure Data Sync to the Preview version.
How to I upgrade from CTP2 to the Preview version of SQL Azure Data Sync?
You can use a standalone executable deprov.exe for this de-provisioning. This executable was installed when you installed LocalAgentSetup msi for CTP2 (If your system directory is C: and you used default path of installation, this utility will be at c:\program files (x86)\Microsoft SQL Azure Data Sync). Latest version of this msi is at the download center now.
Uninstall the local agent.
To uninstall a local agent you:
Open Programs and Features in your Control Panel
Start > Control Panel > Programs and Features
Find the entry Microsoft SQL Azure Data Sync CTP2 and right-click it.
Great job on this, Russ!