C# ActiveDirectory UserPrincipal.SetPassword() ignores password history in password policy

Hi.
 
I am developing a library for active directory operations like authentication, create user, delete user, enable/disable user and change password.
 
My library works fair except a few bugs.
 
Issue #1. When I call...

UserPrincipal.SetPassword(somePassword);

...the password is simply set even if I try with the previous password when the Enfore Password History policy is set with a value 9 passwords remembered. When this policy is active, my password change code is expected to fail because it is a recently used one. But my code simply sets the new password. Any idea about how to fix this?
 
Issue #2. When I set a password, the password is rejected if the complexity requirement is not met. Is there any idea to retrieve the active password policy settings so that I can display a friendly message to the end user?