The tool 'FindGraphicsInHostCoordinates' creates an "InvalidOperationException" message when utilized in a form that is not the startup form.This happens in ArcGIS Server WPF API Version: 1.2, Visual Studio: 2008, and .NET Framework: 3.5.
Tested the issue using the 2.0 beta version of the WPF API for ArcGIS Server and VS 2008, and found that the FindGraphicsInHostCoordinates-Method works as it should (no exceptions).However, ArcGIS Server is built on the Microsoft Silverlight/WPF platform which is integrated with Visual Studio 2010.Thus,2.0 beta version of the WPF API for ArcGIS Server and VS 2008 might work for his specific scenario (FindGraphicsInHostCoordinates-Method), but it doesn't necessarily mean 2.0 beta version of the WPF API for ArcGIS Server is supported for VS 2008.