Has anybody out there used Safe Boot to encrypt hard disks?

We appear to be having problems with Safe Boot where if we install it
before installing the ZCM client, then everytime the ZCM client attempts
to install an application then it prompts for a windows password.

Unfortunately, no password is accepted.

Any ideas as to why this would happen.

It seems that if the ZCM client is installed before the disk is encrypted,
then it works ok.