I'm having trouble getting the GDM login screen to show up when I connect from a remote host. I'm using Xming on the local Windows machine, but every time I connect to the remote server all I get is a gray window with the X cursor. I have "Enable=true" in the [xdmcp] section of /etc/gdm/custom.conf. IPtables is disabled. I've googled around and read through the xdmcp page on tldp.org but have not come up with anything. Can anyone help with this issue?