Can not query xdm server

[tea]

In my gentoo linux I have installed XFree4.2.0 , and can run xdm to get a graphic login console.
But in my another PC of Windows at the same lan with gentoo linux which I installed a X sever (WinaXe) can not query xdm server.
I have removed the # from the "* hosts allowable to connect " in Xaccess file.
And if I start winaxe first , then start xdm (with Xservice file include my windows pc) , I can get a graphic login in winaxe!
I have search a lot and read some howto but can not find what wrong about my configuration!
if someone has experience about it , please give some hint!!
Thanks!!