I got stuck on your step 2 of registration. Here is what happned. I got to the "When do you want to achieve your goal by box" (going from memory here, so I might not have the details exact). Your help text says "2 weeks or by June 4th". So, I assumed I could enter "by March 1st" -- that was invalid, so then I tried "March 1st" -- invalid, then "March 1" -- which it rejected since it claimed that date was in the past.
At this point in time, I had a red box beside the submit button (with the date in the past message), and the submit button had been disabled. I went back and entered "March 1, 2007" and then "20 weeks" which both were accepted as valid, but the submit button never activated again, and I wasn't able to go anywhere.
I ended up breaking the stalemate by clicking the log in button, which redirected me back to page 2 so i could start over.
Hope that helps -- It was neat how you parsed the input boxes for info -- just make sure that being too clever doesn't come back to bite you!