Vendor Registration

-- url of the page with the problem -- : the-authors-club.com
-- HikaShop version -- : HikaMarket Multivendor: 1.3.1
-- Joomla version -- : 3.2.1
-- PHP version -- : Version 5.3.27
-- Browser(s) name and version -- : Internet Explorer 9
-- Error-message(debug-mod must be tuned on) -- : Error_message

User registration is now working as it should, but users cannot register as vendors. According to the emails I've received, after clicking on the "Register" button, they receive a notice that the page cannot be found. Do you have any suggestions that may help me get this fixed?
Vendor registration is under the Authors Lab menu item.

Thanks.

These are my settings:

Allow vendor registration: Automatic validation
Ask currency during vendor registration: No
Ask description during vendor registration: No
Paypal account required: Yes

It worked before I upgraded to Joomla 3.2.0 and I haven't changed anything since then. I recently upgraded to Joomla 3.2.1 to fix the user registration.

Thank you!