Cancelling an Acronis Backup 12 job

I wish to cancel a backup which appears to be running without my starting it.
The PC is running windows 7 Professional 64 bit

I am using Acronis Backup version 12 which is described when I click the "About" button as follows:

Web console service: v.12.0.2607

Backup management server: v.12.0.3622

Backup management console: v.12.0.6081

When I launch backup Exec in Microsoft explorer using Http://localhost:9877/

And observe the Status it indicates that a backup is being performed with 52% complete.

I normally manually start backups and wish to start another backup without waiting for this backup to complete.

How can I cancel the backup that is running (or any backup that is running).
Powerring down the PC and poering up again makes no difference, even with the MMS service stopped (Acronis Managed Machine Service)