I've recently changed jobs and have a new laptop (Dell D620). When I
try to connect to my home wireless network, I get a connection, but I
cannot get an IP address. The little computer with the "roaming" dot
runs for a while, and then it times out.

I tried this with a public wireless AP and it doesn't time out, but I
never do get the IP address, DNS, etc. It just shows a successful
connect and then nothing.

I've tried connecting to my home network with other devices, with no
problems (have been doing this for several years, now). I have WEP
enabled, but MAC filtering turned off. I'm positive I'm entering the
correct WEP key.

OK, so maybe the built-in WiFi in the laptop is broken. So, I tried
installing a Netgear PC Card (one that I've used many times with
another laptop) with the latest drivers and software. Same result!

So, I'm thinking that maybe there is something in the way my new
employer has the laptop setup. What could this possibly be? Before I
go bugging our tech support (who will take away my laptop for several
days while they determine if the machine is physically broken), I want
to see if there are other things that might be the cause.

One thought is that the machine is "registered" to our company's
domain. Would this prevent me from accessing outside networks?
Control Panel, System, Computer Name. Under "Domain" is
mylocaldomain.mycompany.com. Before I take drastic steps, could this
possibly be it? I wouldn't think...

Any ideas?

I've been a WiFi user for several years, now. I've successfully setup
several APs/routers, computers, laptop, PDAs, bridges, wireless printer
servers, and a ReplayTV. But this one has me stumped.

I'm using XP SP2. Windows Firewall is off.

Thanks.