Would it be better to do the following code change from this:

IIF(tmpPOReport.PO_SUFFIX = "00", "", "Change Order " + PO_Suffix)

to this:

IIF(tmpPOReport.PO_SUFFIX = "00", .NULL., "Change Order " + PO_Suffix)

The problem I think is that the object, that the above code represents, holds space in the Detail Band and does not relinquish it. You would think that it would do the "Remove Line if Blank" thing and thereby remove the space it holds in the Detail Band, collapsing the space and narrowing each row.