Help with Linksys WPC11 and Norton Internet Security

I recently purchased a Linksys Wireless - B Network Kit (W11S4PC11)
consisting of a BEFW11S4 (Version 4) router and WPC11 (version 4)
notebook adapter.

My network consists of 2 desktop computers running Windows 2000, using
wire connection into the router and an IBM ThinkPad 380XD with the
Linksys WPC11 adapter running Windows 98SE. I am using Cox as my ISP.
Immediately after installing the equipment, I checked the Linksys
website and updated the firmware of the router to version 1.45.7
(dated Sep 16, 2003). No updates were available for the WPC11 card.

After installing software, drivers and hardware on the notebook
computer, I edited the Default profile as follows: Wireless Mode:
Infrastructure Mode, Network Settings: Obtain an IP address
automatically (DHCP), WEP: 64 Bit, with SSID and WEP Level/Key
matching those of the router.

The notebook has Norton Internet Security 2002 running on it. I ran
the Home Network Wizard and it correctly found the card and router's
IP address and set a rule for it.

Now the problem...

When I boot up the notebook and look at the Linksys WLAN Monitor
program, it states "You are connected to the access point, but the
Internet cannot be found." I can see the notebook from the desktops,
and link to it using Windows Explorer without problem, but no Internet
access from the notebook (the desktops have no problem with the
Internet).

If I disable Norton's firewall on the notebook, I immediately gain
access to the internet. If I re-enable it, then I'm back to the
original situation - connection with the computer via the network, but
no Internet from the notebook.

Obviously there is something that Norton Internet Security is
blocking, even though it found the network and allows communication
with the other computers. If anyone knows of anything else I can try,
I would greatly appreciate it!

Thanks
Dave