Pete d'Oronzio [pdmagic]

SOLVED!

After following lots of advice here and from my ISP, I narrowed the
problem down to my in-house DNS server. (pointing my Vista machine's
DNS directly to my ISP made the system work properly, which is what
made me focus on the DNS server) From there, I narrowed it to the
drivers for my Broadcom NetXtreme 57xx Gigabit cards.

The drivers I had installed (probably what shipped with the card)
were v6.34.4.0 dated 4/17/03. I updated them to v10.24d dated 2/1/07
(Dec 06 on the actual driver)

This has completely solved the problem.

Thanks to everyone here who helped and made suggestions.

-Pete