Answer (from ESRI Tech Support): Using a basemap that has a projection other than Web Mercator Auxiliary Sphere causes the shortlist application to continuously spin and not load.
BUG: NIM099707
They're working on a fix. Alternate Solution - publish the basemap service in Web Mercator Auxiliary Sphere. (This worked like a charm).
Answer (from ESRI Tech Support): Using a basemap that has a projection other than Web Mercator Auxiliary Sphere causes the shortlist application to continuously spin and not load.
BUG: NIM099707
They're working on a fix. Alternate Solution - publish the basemap service in Web Mercator Auxiliary Sphere. (This worked like a charm).