the way you have your rsPROD recordset configured, it is filtered on a form post from the previous page.
when the add to cart button is pressed, that form post no longer exists, so the recordset is empty.
add the following form element to the add to cart form on the page:
<input type="hidden" name="LEDid" id="LEDid" value="<?php echo $_POST['LEDid']; ?>" />
1) the tutorial is talking about the initial set up, it does not address reinspecting the add to cart button
2) after making a binding selection, you may sometimes need to select another column to force the binding to stick.