Okay well lets see here your post meantioned VB
in capitols but there i now see the no in small letters next to it
So this is an internal install
Okay your cookies are fine and as noted the if a person logs in and it says successful and they arent cookied in that means they are not allowing the cookie it looks like to me.
I went to your gallery registered an account and I login fine. Since cookies are set on a user's computer the issue usually means they are blocking cookies. If there was an issue with the software then no one would be logging in. The fact that I can register and login fine suggests those few users are blocking cookies.