http://www.aol.com

There's a section to the right that allows members to log in. I can
log in fine from anywhere but not from one office.

There is a long delay while the browser tries to open a https page (it
seems) and finally returns a page not found error.

It's not an issue of usernames: The same accounts that work fine from
home or other locations do not work from this office.

It's not an issue of computers: I brought in a laptop and it could not
log in either. Bring my laptop to another office, boom, no problem.
Plus, all the IE settings are default. And accessing other https pages
are fine as I can purchase from Amazon or Staples, etc, and log into
hotmail or yahoo accounts.

I have a basic older linksys broadband 4-port router. No filters or
anything like that set up.

We use a SBC-Yahoo DSL connection with their standard modem.

I should go ahead and install the SBC-Yahoo connection software on a
computer and hook it directly to the modem to eliminate the router
from the picture, but that's a big hassle. Besides, how could it be
the router?!?

Save $20. This same thing (same router, same ISP, same problem)
happened to my client yesterday - and was resolved by changing the MTU
setting in the Linksys router from the default 1492 down to 1400.

Now, if someone could explain WHY this is necessary I'd be grateful.