Hello,
I've checked your site and I can't find any problem with the code. The "/" action shouldn't matter, because the form sends data using the post method, and it works in my test environment on Joomla 1.5.15 and JoomSEF 3.5.3 with no problems. I'm sorry, but we cannot offer you more free support with this, as it seems there is some problem specific to your server. If you would like us to fix this directly on your web site, please purchase 1 hour of our support time at
www.artio.net/e-shop/support-services/joomla-related-support-1h and contact me with your order number, admin and FTP access to your website on my e-mail.
Best regards,
ARTIO Support Team