Windows XP + Windows 2000 browsing problem

I have AD-based network on 2 Windows 2000 Server DC with mirrored functions
(DC, GC, DHCP, AD-integrated DNS). All PCs are Windows 2000 Pro. All works
fine.
Recently I install Windows XP SP1 on the one of my PCs and faced the problem.
When I double click a shared folder on Windows 2000 Server or Pro computers
from that Windows XP PC, the browsing process takes unexpectedly long time
before I can see the content. When I click the "Up" button (in order to move
to the shared folder list) and double click the same folder again, the
content appear quickly.
I made some NetMon traces and noticed the following: the data exchange looks
normal, in the first 3 seconds (!) I saw the normal initial (connection tries
only) data exchange, then the silence for 17 seconds, and after that the full
(connection tries + content) data exchange within 1 second.
Does anybody knows how to beat the problem?

The problem closed. Windows XP tries to load directory listing via WebDAV.
The HTTP-port was closed on our router.

"Igor Girkin" wrote:

I have AD-based network on 2 Windows 2000 Server DC with mirrored functions
(DC, GC, DHCP, AD-integrated DNS). All PCs are Windows 2000 Pro. All works
fine.
Recently I install Windows XP SP1 on the one of my PCs and faced the problem.
When I double click a shared folder on Windows 2000 Server or Pro computers
from that Windows XP PC, the browsing process takes unexpectedly long time
before I can see the content. When I click the "Up" button (in order to move
to the shared folder list) and double click the same folder again, the
content appear quickly.
I made some NetMon traces and noticed the following: the data exchange looks
normal, in the first 3 seconds (!) I saw the normal initial (connection tries
only) data exchange, then the silence for 17 seconds, and after that the full
(connection tries + content) data exchange within 1 second.
Does anybody knows how to beat the problem?