This is a copy of the tech support I sent to Acronis today I reported this problem January 10, 2008, incident #1290944. The problem persists in update TI Home 11 version 8101. If a job is configured for incremental backup, with a password set matching the base full backup, deleting the base full backup will cause subsequent incremental jobs to run without enforcing password protection on the archive. The first incremental backup after deleting the base full backup set will have all the characteristics of a full backup, but will not be password protected. All subsequent incremental backups will likewise not be password protected. With this defect, all that is necessary to breach password security on a backup set it to delete the initial full backup of the set. There is no notification that an initial full backup set does not exist. This is NOT how TI9 and TI10 worked. If the initial full backup was deleted, subsequent incremental backups would continue to be password protected.