Hi Lee,
Go to VA02 - Overview - Shipping - there you can see Delivery group 1 for the line items. You can make it blank.
Before that please look the below link on Delivery group and its importance:
http://help.sap.com/saphelp_40b/helpdata/en/dd/560602545a11d1a7020000e829fd11/frameset.htm
Regards, Sai Krishna.
