Why can't I do this in CI?

[eluser]Yunohoo[/eluser]
The code is nowhere near complete so please don't assume anything. I've encountered this error so why would I go ahead and build tons of extra code when I can't get past step one?

I'm simply needing a separate session library to handle "admin sessions" without any interference with regular user sessions handled by CI's session class. This is basically a small session registry for administrators logging into their private dashboard.

I just need help understanding why the session id is not passed onto the session class after the form submission which is clearly should be as shown in the non-CI code.