I am trying to connect to a TMS service.  When I click "Add provider" I get an error saying "(407) Proxy Authentication Required".  I have entered my proxy details into ArcCatalog, and both the Bing and OpenStreetMap options work correctly.

The Details button shows the following:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Net.WebException: The remote server returned an error: (407) Proxy Authentication Required.
   at System.Net.HttpWebRequest.GetResponse()
   at BruTileArcGIS.AddProviderForm.GetList(String Url)
   at BruTileArcGIS.AddProviderForm.InitForm()
   at BruTileArcGIS.AddProviderForm..ctor()
   at BruTileArcGIS.AddServicesForm.btnAddProvider_Click(Object sender, EventArgs e)
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

see the patch attached to https://arcbrutile.codeplex.com/workitem/5229