Internet access issue

I've found that when I try to log in to newegg.com, or do anything else secure
oriented (view my shopping cart, for example) the browser hangs. Hangs both
Opera 9.01 and I.E. 6.0 (with all patches).

I suspect it's a problem with my router, cable modem, or cable service, because
if I use my dial-up connection it works. I'm investigating the cable side, but
I thought I'd check here to cover all the bases.

There's obviously different hardware and drivers used inside the PC for dial-up
vs. cable. The dial up via an AOpen FM56-PM and the cable via a Linksys
LNE100TX. They each have their own drivers installed, the latest as far as I
can tell.

This all worked a few months ago, but I've heard that NewEgg "updated" their
secure system.

Is there anything I should be checking inside the PC? Or can I assume that
with dial-up working this has to be external?

- Bill