Backup/restore of encrypted files fails

Any help appreciated!

I'm using an encryption software (Credant Mobile Guardian Stand Alone Shield) to secure all files on a notebook, including system operating files.
Everything went fine using "Acronis True Image 11 Home", but after upgrading to "Acronis True Image Home 2012" all the files in the backup archive are still encrypted (volume backup and file based backup).
I presume that Acronis has changed the way it accesses the folders and files in the new versions so the encryprtion software is no longer aware that data is moved to backup and does no longer decrypt them (using filtering device driver).

Can anybody say which new mechanism is used (VSS?)

Thanky,
tpk.