Cancel business processes that are sub-pocesses of DCM

Hi,

I have about 70 business process instances currently in status of running. When I try to cancel them using the OOB Cancel execution button I get the message: The process can not be canceled, because it was started as a subprocess.

The parent process of the instances is the 'Order Processing' which is not really a busines process just the order DCM.

How can I force the cancel on those BPs?

Thanks,

Chani