When the system does not recognize Zaptel cards after a reboot:

• Login to the system administration
• Navigate to 'System: Information: Zaptel'
• If the 'Detected Cards' field is empty, navigate to 'Settings: Servers: Zaptel modules' and set 'Unload modules on stop'='Yes'
• Click on the 'Save' button
• Restart the system
• Navigate to 'System: Information: Zaptel' and check under 'Detected Cards' if the card has been recognized