Hi
If you've got os9 as opposed to os9.04 you should update, it's free (and improved)
Different modem scripts perform differently with different setups, I'm not sure I know what you mean by 'clicking'? There was a collection of scripts called 'modem puppet show' search for it using yahoo or whatever. Download and try some of the G3 external ones by dropping them in your modem script folder then choosing them via your modem control panel. Might help, might not. Might be hardware after all.
Good luck