If you are having troubles with your password please try the "forgot my password" link on the login page. You will be emailed a temporary password to the email address you used to create your Cash for Apps account.
Once you've logged in you can change your password easily, just go into the "More Tab" & select "Settings".
If the temporary password still doesn't work and you're getting a "make sure you're online" error message it is because you're connected to an IP address that is being used by too many other accounts. In this case please connect to a different wifi network and try logging in again. Sometimes waiting a couple hours and trying to log in on the same network again also solves the issue.