cannot login with Network User directly from Screen Sharing

Hi,

I am not sure if I'm going to sound stupid, but I just got stopped at one simple step. I am trying to login with my network user to his account on server os x (4.1) using Connect To Server (vnc://) and unfortunately I am not allowed despite putting the correct IP, password and login. And network users have their "allow the user to log in" ticked under Server.app / Accounts / Users. So all seems fine to me.

But when I use the administrator credentials in Screen Sharing (Connect To Server, the same way as with the standard Network User) and then I log out administrator within the Screen Sharing (not closing the window, just log out) I land in the Login Window where I can enter any of my network users without any problems and they can login to their accounts from that Login Window in the Screen Sharing.

Is there any way of allowing Network Users to simply enter their credentials under Connect To Server (vnc://) and directly connect to their accounts using Screen Sharing?

I'm pretty sure there is a simple solution, but I just can't find it. Please help.

P.S.

My server has "Enable screen sharing and remote management" ticked and no custom access specified (all users from all networks can use this feature).

All users have allowed access to Screen Sharing services.

Thanks

T.