I managed to exterminate almost all HTML validation errors in my site.

There is an error, however, that I find somewhat more difficult to spot: In the Gift Certificates page there is one form that is not closed.

Attempting to trace back to the PHP module that creates this form (which has the name "multiple_products_cart_quantity") I managed to find two suspects:
  1. includes/modules/product_listing.php
  2. includes/templates/template_default/templates/tpl_proudcts_all_default.php


In the first suspect, product_listing.php, the last statement in the file, a zen_draw_form() seems to be not closed by a </form>. This is either a bug or it is being closed but in another file. If the latter which file is supposed to close it?

In the second suspect, tpl_proudcts_all_default.php, the </form> at the end of the file is conditional. Perhaps this is the source of the problem? A bug?

In either case, one </form> is missing, as detected by the W3C HTML validation.

Any suggestion or idea how to zero-in on the problem?

Thanks.