activation URL problem

-- HikaShop version -- : Business: 2.3.5
-- Joomla version -- : 3.2.3
-- PHP version -- : 5.3.3

Hello.
I am configuring users registration and I found an incomprensible problem.
Originally, the user activation link at "user account" notification email worked perfect, but when I set Configuration->Main->Cart->"URL where to redirect when the cart is empty" option, causes email user activation link don't work anymore.
Instead of activate user account and redirect to Welcome URL, Hikashop don't activate the user and redirects to URL set in "URL where to redirect when the cart is empty".

Can anybody explain me what is happening?

Anyway, I have a second problem, because if I revert Configuration->Main->Cart->"URL where to redirect when the cart is empty" to blank (hikashop default option) the activation URL redirects to /product/listing and displays "empty cart" message instead of /checkout and a welcome message, which is more logical if you are registering at checkout process.

Where can I change this activation URL and message?.

Thanks in advance

I found problem. Since I am using chrome to register but I have configure Explorer like default browser. Then when I click on activation link Open URL in Explorer instead of Chrome.

Changing default browser in order to use the same browser solve the problem.

Regards