Try to disable iptables. Login as root and write this:
if this returns error, try this (if iptables -F is successful, it wont return anything):
You will get the absolute path to the file iptables (if exists). Copy the path and run:
if this is still returning error messages, try to run:
services iptables stop
Now try your application again. If the thing works, scan your network traffic with Ethereal (http://www.ethereal.com/
), so you'll see what ports do you have to open. To open your ports just use the Firewall GUI which (i'm pretty sure) is installed with RH 9.0.
If the application is not working despite you have flushed iptables, then also use Ethereal, maybe you can find out what's wrong, but if it's working on windows, than i suppose the problem are iptables!