I had this problem as well and just found a fix. Here is a link to the message board where I found the fix:
http://groups.google.com/group/microsoft.public.windowsxp.network_web/browse_thread/thread/85a1a9f2eb6cad3e/65dcd716dea2d2cd?hide_quotes=no#msg_65dcd716dea2d2cdAnd here is the text:
This could be a Winsock catalog error
I have traced several of these problems to improperly configured winsock
LSPs. Run "winmsd" and go to Components/Network/Protocol. Look at the
names in the list, anything with "MSAFD" in it or the "RSVP xxx Service
Provider" should be fine. Anything else is suspect, and uninstalling the
owning program might help.
If that fails or your provider list is empty, you may need to rebuild the
catalog from scratch. The following instructions will rebuild your catalog
for TCP/IP. If you are using any other transports (If you don't know, then
you probably aren't) then you will have to reinstall them as well.
1. Backup and delete the following registry keys
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Winsock
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Winsock2
2. Reboot
3. Go to the network connections folder, right click the icon for your
network connection, and select properties.
4. Click install, choose "protocol", and click "add..."
5. Click "Have Disk...", enter "\windows\inf", click OK
6. Select "Internet Protocol (TCP/IP), click OK
7. When the process in complete, reboot
--
Ken Wickes [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.