IBatisNet - HashCodeProvider.GetIdentityHashCode

[Ron Grabowski]

public static int GetIdentityHashCode(object obj)
{
 System.Reflection.MethodInfo methodInfo = null;
 Type type = typeof(object);
 methodInfo = type.GetMethod("GetHashCode");
 return (int) methodInfo.Invoke(obj, null);
}

Why can't we call:

public static int GetIdentityHashCode(object obj)
{
 return obj.GetHashCode();
}

Does using reflection call the framework's GetHashCode method even if the 
object has overriden it?

Can we cache the MethodInfo?

public class HashCodeProvider
{
 private static MethodInfo getHashCodeMethodInfo = null;

 static HashCodeProvider()
 {
  Type type = typeof(object);
  getHashCodeMethodInfo = type.GetMethod("GetHashCode");
 }

 public static int GetIdentityHashCode(object obj)
 {
  return (int)getHashCodeMethodInfo.Invoke(obj, null);
 }
}