Can't access AdminCP

[ElecMoHwk]

I'm having an issue acessing AdminCP with a newly installed forums site. I built a new server, installed the forums, and everything worked fine here at the home LAN. 2 admins, and a handful of users.

I put the box into a colocation facility last night, and came home. Tried to log into the forums and they work. Try to log into the AdminCP and it gives me the "Thank you for logging in, now redirecting you" screen for a second, then returns me to the Username/Password box.

If I choose options in the login screen I can change the coloring of the admin login box for the next time it pops up, however I can't log into the AdminCP and do anything.

Any ideas?

Everyone can log into the forums themselves though, and they work fine.

With this script...

rebuild_option_cache.php