Part II - Enhanced Features > How TOs and FAQ > Troubleshooting - Outgoing calls:
If a character like # has to be added after each phone number (postfix), configure this option in Expert Settings, TAPI Driver.
Help URL: http://www.helpserver.biz/onlinehelp/cdc/oem/3.0/help2000/index.html?howto_troubleshooting_outgoing-_postfix_necessary.htm