I have tried to setup a Gift Certificate product as described in FAQ section but I have problem to order GC.
At the last step, when I confirm the order I got this error message from the server:

Warning: Invalid argument supplied for foreach() in /hsphere/local/home/mivanovi/mom4kids.nl/includes/classes/order.php on line 750

Warning: Cannot modify header information - headers already sent by (output started at /hsphere/local/home/mivanovi/mom4kids.nl/includes/classes/order.php:750) in /hsphere/local/home/mivanovi/mom4kids.nl/includes/functions/functions_general.php on line 41

Anybody knows how this can be fixed?

Thanks.