Upgraded W2000 to WinXP SP2, cannot connect with Verizon Broadband

I upgraded an IBM Thinkpad T21 from Windows 2000 Professional to Windowx XP
Professional. I had been using Verizon Wireless Broadband with their PC5740
card with no problems under W2000. After upgrading to XP, I had all sorts of
connection problems. After first upgrading, the connection was extremely slow
and showed all sorts of activity when I was not even accessing the internet.
I suspected a virus and did find some Trojan viruses that I removed with
Norton and XoftSpySE. Still could not get any kind of decent connection. Then
upgraded to SP 1, still no connection. Then upgraded to SP 2, still no
connections.

Currently, when I connect to Verizon Broadband, it will start to load a
webpage, but then the connection in IE fails. If I examine the connection
properties, it says I am still connected, but I get a failed to connect error
if I try to reload a page or load another page. This behavior is pretty
consistent. I will get a connection initially, but before it even finishes
loading a page it fails.

I have tried all the fixes I can think of. Tried Winsockfix, followed manual
instructions for repairing Winsock and TCP/IP with no success.

I know the wireless card works because I am using it on this computer with
Windows 2000 with no problems.

I'm stuck.... any help would be appreciated.

Thanks,
Dave

p.s. IE version 6 and after losing the connection, network diagnostics show
"no connection" even though the dial-up connection properties still shows
connected. So I don't think it is an IE problem.