Note that the Purchase Order due list is sorted by Delivery Date by default. You might have to scroll down to find your entry. Additionally, please note that the Maximum number of hits in SNC is set to 100 by default; You should always remove this default value and leave the setting blank. Watch the Queries tutorial or read the relevant section in the quick reference guide to see how to change this. Note that queries producing a large number of results will cause low system performance.