Wrong case-sensitive check on computer account names
Simptoms:
The gateway has ports defined, but every time the monitor window is opened, all appears as <Skype port disabled>. Additionaly, on every atempt to start the service, it stops immediately, the monitor displaying "Failed to start the service". Attempting to start the service from Windows service control panel leads to a message such has "Service started then stopped".
Resolution:
In the File/Settings.. dialog, set an all-lowercase prefix name, without any uppercase character.
Issue link:
http://www.3cx.com/forums/failed-to-start-gateway-service-10507.html