The message "Please note your license is invalid and your
software has stopped loading calls.", points to something changing
on the PC and therefore subscription has expired.
The message "Following ratebooks are invalid for your license
information and the calls will not be costed
za_telkom
za_vodacom_talk500", could ge that you loaded a ratebook that was
released after the TNG version that you are running.
Please re-register the TNG.
Under investigation!