More what I'm wondering is if anyone has hit this error before, and what it might mean. To make sure it wasn't my layer that was causing the problem, I have used multiple layers and I am currently trying with one of the ESRI base layers:
var layer = new ArcGISTiledMapServiceLayer('http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer');
Using Fiddler, I've also noticed that when I do this, no http request is made to the endpoint.
Any help on this would be greatly appreciated.