Hm, somehow your page-editing software appears to be deleting or misplacing the hidden form field tag <input name="on0" type="hidden" value="Please Select One">, which is included in the code provided in Seller Admin; if that tag is missing from the button code, the value of the selected menu item can't be passed to the cart. I did find that tag sitting all by itself further down in the page, outside of the button code it belongs to; not sure how it got there, but it needs to be between the <form ...etc.> and </form> tags of the button code. You might try saving your page directly from the raw HTML view after you paste in the button code, rather than switching back to visual-layout mode before saving.
