Using the following ExpandableObjectConverter-derived class leads to a most
strange issue. The ConvertTo method receives an 'Object value' argument that
is supposed to be of my own Style class. That Style class is used as the
type of several properties in my custom control.

Now that works fine while there is only my control on a form. But after
another control of any kind is added, some strange things begin to happen -
from time to time the 'Object value' arguments passed to the convertor
cannot be casted any longer to the Style class - neither using
'(Style)value' nor 'value as Style' constructs. The funny thing is that the
watch in VS debugger really shows the value object as a Style instance with
all its members having appropriate values.

Can anyone please explain why ConvertTo is called with a value that cannot
be casted to my Style class, and still the debugger shows that value as a
perfect Style instance in the watch window? Thanks in advance, any logical
explanation will hopefully save me from utter madness.

internal class StyleConverter : ExpandableObjectConverter
{
 public override bool CanConvertTo(
  ITypeDescriptorContext context, Type destinationType)
 {
  if (destinationType == typeof(InstanceDescriptor))
   return true;

  return base.CanConvertTo(context, destinationType);
 }

 public override object ConvertTo(
  ITypeDescriptorContext context, System.Globalization.CultureInfo culture,
  object value, Type destinationType)
 {
  Style style = value as Style;
  if (destinationType == typeof(InstanceDescriptor) && style != null)
  {
   ConstructorInfo info = typeof(Style).GetConstructor(
    new Type[] { typeof(string) });

   if (info != null)
    return new InstanceDescriptor(info, new object[] { style.Store() });
  }

  return base.ConvertTo(context, culture, value, destinationType);
 }
}