Please help: XDMCP connection dog-slow

[PD Dr. Edward Wornar]

Hello,

sorry if this is a bit off-topic but I was unable to find information in 
the mailing-list archives/Howtos.

I have a linux server (Mandrake 8.1) and several Windows clients
running cygwin/xfree-4.1 (plus one linux client). On some of the win98 clients,
XDMCP is *extremely* slow so it literary takes minutes to get the login screen
and log in. They all are in my /etc/hosts file, they
seem to have exactly the same protocols running, but while some react
very snappily, others are extremely sluggish. Maybe anyone can give 
me a clue what might be wrong? (I am not familiar with
TCP/IP interna, so I'm not capable of interpreting the output of
tcpdump but I can mail it to anybody willing to help.)

Cheers

Edi