Why can't I log into the forums and main page at the same time?

[PolymerBoy]

Basicly, I can only be logged in on here, or on the main page. Plus, if I log in on the main page then log out, I still cannot log into the forums until I change my password.

[Kalbintion]

As far as I'm aware, the main technicpack site and the forums use separate user accounts.