We've received a couple of reports of this. What appears to be happening is the cc-control PID file is somehow getting removed from /usr/local/centovacast/var/run/cc-control.pid, while cc-control itself is still running. I'm not sure what could be causing this, as we haven't made any changes to the PID file handling code in ages.
The latest build (just released) includes some protective measures to guard against an accidental double-startup of cc-control but we're still trying to determine what's causing cc-control.pid to go missing for some clients.