When installing a new AGI script, sometimes Asterisk seems to reporting that the file gets executed with result 0 while the file it is not in fact being executed at all.
If it does not, there are a few possible reasons:

1. the script does not exist at the given agi-bin location or it is not "visible" to the user running Asterisk (solution: update unix file permisions)
2. the script is not executable - try running it manually (do a "chmod a+x queueDial.agi")
3. the script is in DOS mode - i.e. uses CR/LF as the line endings - and won't start from the shell (do a "dos2unix queueDial.agi" to fix it)
4. check if the file /var/log/asterisk/agi-log.txt is read/writeable by Asterisk