As I start to develop sample Flex 3 and 4 apps that including the Ribbit (http://www.ribbit.com) library and functionality I noticed that the example on Ribbit's site on how to log into the account is incorrect. They list, in thier example (http://docs.ribbit.com/index.php?option=com_content&view=article&id=59:sms-and-ribbit&catid=38:flex-articles) to login you use this:

request.login(username, password, devID, appID);

However, everything I did it that way, I get a 'Expected 5 arguments and only got 4' error due to the ILoginParam is missing.This was driving me nuts!

Here is the solution that works:

public function initApp():void {
                var loginParam:ILoginParam = new LoginParam();   //Creates an ILoginParam Object
                 loginParam.username = "myaccountusername";   //These next 4 lines fills it
                 loginParam.password = "mypassword";
                 loginParam.devID = "wkolcz";
                 loginParam.appID = "wkolcz_SampleProject";
                 request.login("", "", "", "", loginParam);  // Pass in empty values for all aurgments except the ILoginParam object
                request.authenticationManager.addEventListener(AuthenticationEvent.LOGGED_IN, afterLoginFunction);  //Listen for it to finish logging in
                request.authenticationManager.addEventListener(AuthenticationEvent.LOGGING_IN, loggingIn);  //Listens while it is logging in
                request.authenticationManager.addEventListener(AuthenticationEvent.ERROR, errorInLogin);  //There was an error in the login
               
            }

This will allow you to login to your account and then listen for it logging in (setup) and when you login (to fire off what ever functionality to want) and if there is an error in the login process.