I found the solution !!!
If your FDS server is running on a separate server than your
CF server you need to include a configuration file when defining
the Flex2CF gateway instance.
On the CF server edit the file (path may vary depending on
platform, this is OS X):
/Applications/JRun4/servers/cfusion/cfusion-ear/cfusion-war/WEB-INF/cfusion/gateway/config/flex-messaging-gateway.cfg
and add the appropriate reference to your FDS server (IP
restrictions, etc)
add this full path to the Configuration File field when
defining the Flex2CF gateway instance
Steve