I think when you get a message like that, it's because you need to set up your start weight and goals in your Sparkpeople settings, not the ticker itself. The ticker generates based on the information in your profile.
To check this (or add it) Go to your start page and look on the left side. Scroll down to My goals and progress, and look for weight progress.
There should be a little red link under that that says "change" - go there, and you should be able to double check your goal settings. Here's a direct link for you: www.sparkpeople.com/myspark/weight_edit.as
There's a section there towards the bottom that says "For your weight ticker you can edit your starting and goal weight: "
Make sure that info is filled out, and save, and see if your ticker will behave then. Let me know if this helps!