What was found
IRREGULARITY REPORTED BY CREW: A SERVICE DOOR WAS REPORTED BY CREW INTERMITTENTLY SHOWED OPEN AND THEY REJECTED TAKE OFF, THEY CALLED MOCC AND REFERRED HIM TO THE MEL 52-3-1 IT WAS A REGULAR OCCURRANCE WITH THIS AIRCRAFT, READ THRU THE MEL BUT THEN WANTED A GUARANTEE THAT THE DOOR WOULD NOT OPEN IN FLIGHT, TOLD HIM THE DOOR WAS VERIFIED CLOSED AND LATCHED AND REF THE PIC IN APP #1 52-3-1, HE WAS GOOD TO GO, BUT THAT IF IT CAME BACK IN FLT HE WOULD HAVE THE NUISANCE MSG. HE AGAIN WANTED MY GUARANTEE THAT HE DOOR WOULDN'T OPEN.