DirectorySecurity RemoveAccessRule issue not removing special permissions

Sort of a strange issue here...

 I set permission on a folder suing the following code.

 
AddDirectorySecurity(path, account, FileSystemRights.ReadAndExecute, InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit,
PropagationFlags.None, AccessControlType.Allow);

 
public static void AddDirectorySecurity(string< ...