The login code is good and works fine (I tested it outside of the component) but it needs some finishing touches / testing
Are you using the latest stable version? The latest is 2.5.1- http://techjoomla.com/invitex.html#bn.
As we had released a beta which you might have used. Please contact our support for help with this. It would be great if you revise your review once you have done this!