Ghost: Two independent backups of the same drive?

Hi,

 

how should Ghost be configured to use 2 independent backup jobs of the same drive? Both backup jobs should only backup new files since the previous backup (incremental?), that is, not a full backup every time.
I tried, but the second backup job always makes a full backup.
I'm using 2 separate USB hard disks for the backups (alternating every third month).

 

Backup A
  Type: Recovery Point Set
  Destination: F:\Norton Ghost Backup\
  For this backup I'm using USB hard disk no 1.
 
Backup B
  Type: Independent recovery point (it was not possible to choose anything else)
  Destination: F:\Norton Ghost Backup\
  For this backup I'm using USB hard disk no 2.
 
Maybe the problem is that both backup jobs are using the same path? (F:\Norton Ghost Backup)

Message Edited by Spooky on 03-18-2009 11:28 AM