[Users] oVirt 3.2: impossiible to delete a snapshot?

oVirt 3.2 with node f18 and engine another f18 and ovirt stable repo. After I create a snapshot of a powered off win xp VM, I then select the snapshot and select "delete" Are you sure you want to delete snapshot from Wed Feb 27 07:56:23 GMT+100 2013 with description 'test'? ok Error: winxp: Cannot remove Snapshot. Removing the VM active Snapshot is not allowed. Is this expected? Why? Thanks, Gianluca