Unfortunately, problem is in base catalog specification where is larger x smaller and PCF file (which is input for ISOGEN) catch that order an post it on N.S. in material list. I don't see any Isogen switch to correct that. But usually clients don't complain about it.
However, there is one thing in I-configure which is called Display SmallxLarge NS, in Materials/Drawing Material List/Setting. There is some input table for that, but I don't know how to prepare it.