Hi Eric,
The 100xx reports are designed (by Microsoft) in such a way that ReportExtensions (What SOD creates to add fields to them) doesn’t work for line elements on the reports. The lines are shadow-copied and the lines that prints are from the shadow-table. It’s not possible to add fields to the shadow table.
It’s beyond the Simple Object Designer capabilities to work with the lines on these reports.
Have you tried report 1306 instead?