DirectoryEntry.Invoke giving COMException for SetPassword when creating a new user

I am trying to create a new AD user using the DirectoryEntry class in C#.  I create an OU, then I create the user (via container.Children.Add()), set some propertys, commit, then try to invoke "SetPassword".  Invoking "SetPassword" is generating the following exception:
System.Runtime.InteropServices.COMException (0x80020006): Unknown name. (Exception from HRESULT: 0x80020006 (DISP_E_UNKNOWNNAME))
   at System.DirectoryServices.DirectoryEntry.Invoke(String methodName, Object args)

Curiously, if I delete the OU, and run my code again, then everything works just fine.  I don't know why it always give an exception the first time I run the block of code.

I am testing on a virtual machine so I can revert to a snapshot that I took before running my test.
Start Free Trial

1:
2:
3:
4:
5:
6:
7:
8:
9:

DirectoryEntry NewUser = contain.Children.Add("cn=NewUser", "MyCustomSchema");
NewUser.Properties["sAMAccountName"].Add("NewUser");
NewUser.Properties["Prop1"].Value = "*";
NewUser.CommitChanges();
 
// This line crashes the first time around
NewUser.Invoke("SetPassword", new object[] { "password" });
 
// Finish setting the user properties and commits