Closed Unassigned: .NET 4.0 Managed Browser TabContainer Not Firing End Requests OnClientActiveTabChanged [27898]

I'm running a web forms application with .NET 4.0 that renders in the .NET Browser Control. The page uses a Tab Control and for some reason the On Active Tab Change Event is not triggering an End Request. I've put alerts in the javascript code and am not seeing it occur. I also am not getting any errors in the OnAsyncPostBackError. It runs the Begin Request Event and the Postback but no End Request.






Here is my setup

.NET 4.0 Browser Control
IE 11 on a virtual machine running Windows 7
Ajax Control Toolkit version 15.1.2.0
IE 11 Compatibility Mode
Web Forms Application