Sub Site logins and Registrations doing strange things

When I try and register a new account from a subdomain site.. ex.
It takes me to
Process should be.. User registers and is taken back to the subsite they registered through.
So I should end up back at :

Also if I try and Login to using the Login Option in the site meta.
It brings up the login form.. I enter details.. then it takes me to the main site
(And shows me as Not logged in)
If I then return to I will be logged in.

Shouldn't I be able to just login to the network through

Am I missing something here?