That's odd... If you press "C" MoBo should plot a contact.
What color is the "node"?
If it's a red square, then you are plotting a contact. There just isn't a visible speed/heading vector. To assign the vector to the contact, just hover over the contact and press "V" and the speed/heading gadget will appear to let you set the vector.
It should only plot a node if you press "N" and it should be a small blue circle.
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