Aha!

[dmorin at lear.morinfamily.com (Duane Morin)]

[You know, if people want me to take this elsewhere I can, seeing as this 
is a Linux group and this is clearly not a Linux problem.  However, it 
seemed like more of a router/tcpip problem than necessarily a Windows 
one.]

Ok, I have new evidence.  I took both my Windows machines (XP and 2000) 
downstairs and plugged them directly into the router -- both still 
exhibited the same problem.  Then individually I went around the router 
and plugged each of them dircetly into the cable modem.

Both worked just fine.

My paranoia that ATT was somehow trying to keep me to using 1 PC has 
abated.  Now the only logical conclusion I have left is that my router is 
somehow not forwarding my Windows traffic.  That would imply that the 
Windows stack is somehow identifiable different from a Linux stack, which 
I'm not sure is correct.  But the evidence is right in front of me -- 
Linux boxen plugged into the router work fine, Windows boxen all exhibit 
the same problem, Windows boxen that go around the router do not exhibit 
the problem.  Ergo, must be the router.  Of course I haven't touched the 
router in weeks, but still, I suppose hardware does fail.

For completeness, I told the router to mimic the MAC address of my XP box 
-- didn't help.  Besides, I connected two different boxes directly to the 
cable modem and both had different macs and worked ok, so methinks that 
their detection of your registered mac leaves sometihng to be desired.

I shall call Linksys now.  If anybody's got any guesses, I'm all ears.


Duane