What fop2 version are you using? How are you trying the dial? Try by typing some number and hiting enter, and also by searching on a phonebook entry to see if it makes a difference. I have set that myself and it works for me, but I am not using device & user mode in FreePBX. Not sure if you are using that mode or not. In any case, you must start fop2 server in debug mode to intercept the manager events and responses:
service fop2 stop
cd /usr/local/fop2
script capture.log
./fop2_server.pl -X 511
(log into fop2 and try a dial)
ctrl-C (to exit fop2)
exit (to exit script capture)
You will end up with a capture.log file to inspect. In any case, you might also want to try with the latest beta, you can find download links in the announcement forum, as I think there is a bug fix related to the dial box, but not sure if it applies to non device&user mode setups.
