I've already replied to your support e-mail about this, but for the benefit of any others who might be reading this...
The access denied message means that the OS on your target machine is denying access to the specified folder, either due to permissions set on the target folder or because another process is locking the file. If you haven't customised any of the folder security settings, the most likely culprit is a virus scanner.
Project Manager - SQL Compare|Data Compare|Comparison SDK
Redgate Software Ltd.