xhost problem

[Gary Aitken]

I can't get an xterm from another machine to display on my 5.3 system.
I've tried xhost with the ip of the machine I want to allow in,
and finally tried xhost + to allow any machine in,
but attempts to display still fail with "Can't open display w.x.y.z:0.0"

firewall_enable and ipfilter_enable are NO at the moment,
and the source (xterm) system is open on the internal network.

What am I missing?

Thanks,

Gary