Are you sure you have the correct email address and password? You might try changing your password to something extremely simple temporarily, just to make sure it's not a problem with an odd character in your password. You can change your password here.
Oh, and make sure you enter your email address when you log in, not your username. That's a frequent problem people encounter. (And something we have on our to-do list to fix.)
Beyond that, you might also make sure your Blackberry browser is set to accept all cookies from Fuelly.