I've also been experiencing extremely slow web response from AT&T's sites for over a week now. It doesn't matter which computer or web browser I use; nor does it matter whether I'm in or outside of my business or personal home networks. Firewalls enabled or completely vulnerable to attack...still very inconsistent in even being able to log on or do anything within my account when I finally can get logged on.
Their website is the most frustrating experience I've had since dial-up back in 1996.