We noticed that in Sales under the shipments tab EVO does not show the "customer PO" either.  Our salesmen use this in DBA.  Is there any way to get it back?

You can edit the grid display that you see in IN-A, Shipments.  Go to the menu: Querries-SU-A, select Grid Name "INV_HIST_LINE".  In the "File Name" box, select "BKARINV".  Next, in the second empty "Links & Notes Fields" box, select the field "BKAR.INV.NUM".  Now go down under the "Field Data" box to first empty line after "Ext Price".  title this "Customer PO Number".  In the "Field Name" box next to this title, select "BKAR.INV.CUSORD".  I then go back to "File Name" box in upper right corner and change back to "BKARINVL" , then click save.  
 
The customer PO should now appear in your Evo IN-A shipment screen.