Cannot search Drug when editing Obs

On Demo (please log in before clicking links) in the obsForm.jsp when editing the Obs with Concept Question TRAC-1088 you cannot search for a Drug in the ConceptSearch widget such as STAVUDINE TRAC-625 even though you can search for other concept answers such as TENOFOVIR TRAC-802 Notice that both of these concepts are answers to Concept 1088, and both are Concept Class=Drug; difference being that STAVUDINE TRAC-625 is listed in the Drug table where TENOFOVIR TRAC-802 is not.