Firewall on Linux
On SUSE Linux, the firewall configuration may prevent the Draw demo from running successfully. If you run Draw and it opens the application window but you can't draw in it, the issue may be your firewall. See Davor Cengija's blog for a description of how to resolve this issue.
On RHEL/Fedora edit /etc/sysconfig/iptables adding:
-A RH-Firewall-1-INPUT -p udp -d 188.8.131.52/4 -j ACCEPT
at the top of RH-Firewall-1-INPUT rules and reload with:
service iptables restart