ArcGIS Legend Widget Test Result for jtlewis
I ran the widget on your service link. It worked fine with me. Here are the screenshots.
Well, for the testing purpose, the layer was the only one in the OperationalLayers tag. Have you tried to test the widget only on that URL in your environment? Did the widget fail on any other layer in the same host server? If you could send me the error message, I would look into further for you.
I am guessing... Could it be you have too many layers, causing the timeout?