Sounds like you don't need bi-directional syncing, but handling locked files is critical.

I know just the (free) program for you: HoboCopy http://www.pluralsight.com/wiki/default.aspx/Craig/HoboCopy.html

What is HoboCopy?

HoboCopy is a backup/copy tool. It is inspired by robocopy in both name and in functionality. It differs greatly from robocopy, however, in two respects:

   1. It is not as full-featured as robocopy.
   2. It uses the Volume Shadow Service (VSS) to "snapshot" the disk before copying. It then copies from the snapshot rather than the "live" disk.

...

Why Does HoboCopy Use the Volume Shadow Service?

Because HoboCopy copies from a VSS snapshot, it is able copy even files that are locked by some other program. Further, certain programs (such as SQL Server 2005) are VSS-aware, and will write their state to disk in a consistent state before the snapshot is taken, allowing a sort of "live backup". Files locked by VSS-unaware programs will still be copied in a "crash consistent" state (i.e. whatever happens to be on the disk). This is generally a lot better than not being able to copy the file at all.

It belonged here:
https://www.donationcoder.com/forum/index.php?topic=7091.msg51529#msg51529

Thanks!

Earlier it was asserted that NTFS encryption can be decrypted on a different system if one just moves some registry keys. This might be true for XP in a standalone or workgroup configuration, but it is decidedly not true if you're in a domain.

If you attach the drive to a different domain, or if you lose the domain controller, you will NOT be able to decrypt the data. And since the idea here is to keep a backup secure, one must assume that the reason for restoring the backup might be that the domain was destroyed.

So, I second the recommendation of TrueCrypt.