An Strange Error: about User Control

[wxuf]

hi;

I am working with the usercontrol in the past days, I found a very strange problem. (Maybe a bug of VS2005).

First time I create the user controls in an Assembly named XControls, the main application will use this assembly named TestApplication. When I am drag my created user controls into the Main Form. But it seems that sometimes I success in doing this. But sometimes I failed with the following error Message:

Failed to create component 'UserControl1'. The error Message follows:
'System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
 at System.Reflection.Module.GetTypes()
 at System.Reflection.Assembly.GetTypes()
 at Microsoft.VisualStudio.Shell.Design.AssemblyObsoleteEventArgs..ctor(Assembly assembly)
...

While the same phenomenon does not appear regularly, but rather randomly.

Hope someone can help me.

wxuf