What you just posted describes an illegal connection that shouldn't be there.  You can connect a Specular node to Alt. Specular but you cannot connect it directly to the Specular channel.  I bet if you check the Material Room, you will see a dotted connector between the two nodes.  A tip, whenever you're connecting nodes, Poser will gray out the connectors of the input node indicating that those are not legal receptors.  You can still connect but don't expect good results.  Always check the preview to insure that calculations are properly done, otherwise, you will get a black preview.