Hi Dan
What is happening is this - since we have all the months [12], all the dates [31] and years[1921 through 2011] in the form fields, the robot seems to be taking these incrementally and then using the submit button. After the submit button, user is presented with a registration page. While we do want the search to index the rest of the page and the crawl through the rest of the page links we do not want it to crawl through that submit button. I hope I am making sense.
Naren