Vista has a new tool called robocopy that can be used in place of a backup
program to make a copy of encrypted files. Robocopy will retain the EFS
metadata on the files. You would need to run it at cmd line in this format:
robocopy <source> <destination> /efsraw
Be sure to also back up your EFS certificate and key to (non-encrypted)
removable media. Help and Support has directions for doing that or you can
use the new EFS tool in Control Panel's User Accounts: "Manage your file
encryption certificates."
Thanks.
Pat