Mapped drives browse Windows 2000 shares SLOWLY

We have a windows 2000 peer to peer network using the TCP/IP protocol.
A couple of our guys just upgraded to windows xp because that's what
came on their laptops.

For some reason, although a Windows 2000 computer can browse the
shared network drives (we map a drive letter to the share on the server)
rather quickly, Windows XP is slow to the point
that the computer is unusable. Two minuntes just to do a directory
listing on the server harddrive, and that's only a 2GB drive.

Following the advice of some sites on the Internet, I turned off
Indexing. However, the problem still persisted.

My network setup.
Windows XP Pro:
Installed...
1. Client for Microsoft Windows
2. QoS Packet Scheduler (turning this off has no effect either way)
3. TCP/IP

IP Address: 192.168.0.100
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.0.1 (the proxy server)
Primary DNS: 192.168.0.1
Automatic Metric


Server:
Windows 2000 Professional:
1. Client For Microsoft Windows
2. TCP/IP

IP Address: 192.168.0.30
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.0.1 (the proxy server)
Primary DNS: 192.168.0.1


Notes:
-- Windows 2000 clients have no problem. The network connection is
instantaneous.
-- From the command prompt of Windows XP, the mapped drives can be
accessed instantaneously.

For those reasons, I think the problem is a task that Windows XP is doing,
and not a virus or DNS setting. I turned off indexing. Is there
any way I can troubleshoot this problem?

Thanks!
Tom

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