The first diagram will be drawn correctly, any update on the model lets the name of the graph (smallgraph in this case) appear in the top left corner of the graph, although it should not appear there.
Additionally, turning default values off and on again lets the node labels disappear until the nodes in the model are renamed.
Open a .kgt file such as this one when default values in the diagram options are turned on:
The first diagram will be drawn correctly, any update on the model lets the name of the graph (smallgraph in this case) appear in the top left corner of the graph, although it should not appear there. Additionally, turning default values off and on again lets the node labels disappear until the nodes in the model are renamed.