cannot get XDM on remote RH 8

[amr roushi]

I am running on W2K with XF86 and running fine with AIX & SUSE I get the 
xdm login via
 xwin :0 -query hostname -from hostnameHere .
all addresses are resolveable and XDM enabled .
when doing this to the redhat Nothing happens and also nothing in the 
XF86 log .
thanks for ur help