Confirmation in error in process

Hi SAP gurus,

I have one limit Po with time frame (say for example 10.03 to 10.06), when i am trying to create confirmation after the time frame i.e. 10/06 , i am able to create confirmation but it goes in error in process. While checking it does not show any error. In RZ20 we have error in creating service entry sheet in backend. We are in SRM 7.0 using ECS.

Is there any configuration settting in SRM, so that we can stop creating confirmation in first place. While creating confirmation it should show SRM error as time frame is in past for purchase order.