I configure VirtueMart with this parameters:
site URL:
www.mysite.com/
security URL: https://shared_ssl.com/
When I use standart Joomla template everything is correct.
When I use RT template, the Joomla doesn´t save the registration by Register Login:
.../index.php?option=com_virtuemart&page=shop.registration&Itemid=21&vmcchk=1&Itemid=21
When I use the cart to buy something, it is possible to save:
.../index.php?page=checkout.index&ssl_redirect=1&option=com_virtuemart&Itemid=21
If I use the same URL in site and security (http or https), Joomla save the registration.