Classifieds plugin - login redirect?

I found when a user is not loged in and tries to post an ad it redirects to a special login page. The problem is i have set up cusome login pages already and this page is confusing to users as well as the fb login (for a seperae plugin) does not appear. Is there a reason for this page or can it just be set to not be used and redirect to the login page we have set up prior?

If it can be removed please advise the best way to do so.
Thank you