Unknown exported as GPML is exported as Label not DataNode

What is causing that after exporting "exported as gpml" map to CellDesigner, the Unknown element is display as TextArea not species.

• original CellD file: element1.xml
• above CellD exported as GPML: element1check.gpml
• above gpml exported as CellD: element2.xml
• original gpml: unknown.gpml

Unknown element exported to GPML:
<Label TextLabel="element1" GraphId="sa1"> <Comment></Comment> <Graphics CenterX="260.0" CenterY="136.0" Width="70.0" Height="25.0" ZOrder="2" FontSize="12" Valign="Middle" Color="000000" FillColor="cccccc"/> </Label>

Original GPML:
<DataNode TextLabel="Unknown" GraphId="d45e0"> <Graphics CenterX="483.0" CenterY="226.0" Width="80.0" Height="20.0" ZOrder="32768" FontSize="10" Valign="Middle" /> <Xref Database="" ID="" /> </DataNode>