sap Q info record valid from date

Hi,

I am trying to set up a scenario where I cannot order from a vendor in case the delivery date on the PO line item is after the release date on the Q info record. I have the PO block set in the drop down and have assigned the QM control key in the material master with the block inactive checkbox deselected. The delivery date on the PO line item is 11/05/2013 (MM/DD/YYYY) and the release date is 11/27/2013 (MM/DD/YYYY). I was expecting the PO to be saved with no issues but somehow it gives me the error "Procuement ot material xxxxxxxx blocked for quality reasons" Can any one tell me what is causing this to happen ? What I am looking for is to have PO with delivery date of 11/26 or before to be created but any POs with delivery date of 11/27 or more to be blocked.

Thanks