FALSE WARNING - ACR CREW RECEIVES A GPWS WARNING IN THE SAME GENERAL AREA TWICE. THERE IS SOME HIGH TERRAIN IN THE AREA; BUT IT WAS WELL BELOW THE NORMAL WARNING PARAMETERS.

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LEVEL AT 10000 FT MSL ON THE LOCKE 1 ARR TO SFO AT LOCKE WE WERE VECTORED TO A 280 DEG HDG TO INTERCEPT THE RWY 19L LOC AT SFO. SHORTLY THEREAFTER WE WERE CLRED TO DSND FROM 10000 FT TO 7000 FT. AT APPROX 8000 FT WE RECEIVED A GPWS WARNING 'PULL UP' 'TOO LOW TERRAIN.' WE ACCOMPLISHED OUR SOP EMER. PROC (MAX PWR 15 DEG PITCH UP) PASSING THROUGH APPROX 9500 FT THE WARNING STOPPED AND ATC WAS INFORMED OF OUR TERRAIN WARNING AND CLB. ATC TOLD US THE MINIMUM VECTOR ALT AT OUR POS WAS 5000 FT. HE THEN CLRED US TO 7000 FT AGAIN AND WE EXPERIENCED ALMOST THE EXACT SAME EVENT. THIS TIME THE CTLR TOLD US THE MINIMUM VECTOR ALT WAS 3000 FT. AFTER FURTHER EVALUATION WE ACCEPTED ANOTHER VECTOR TO ILS RWY 19L SFO AND LANDED WITHOUT EVENT. MAINT CHKED THE GPWS COMPUTER AND FOUND IT OPERATIONAL. WE WOULD NOT TAKE THE ACFT UNLESS THE COMPUTER WAS REPLACED AS WE WERE TO FLY 2 MORE LEGS IN THE SFO AREA IN HVY WX. THE ACFT WAS THEN TAKEN OTS. WE TALKED TO THE CTLR ON THE PHONE AND HE AGAIN ASSURED US THAT WE WERE CLR OF ALL TERRAIN. WE EXPLAINED THAT WE HAD TO FOLLOW OUR PROCS AND CLB; WHICH HE ACCEPTED. MAX PWR CLBS IN IMC WITH GPWS WARNINGS ARE NOT COMFORTABLE MANEUVERS. HOWEVER; OUR TRAINING AND PROC SERVED US WELL. I WILL CAUTION OTHERS THOUGH; THAT IF YOU REALLY KNOW WHERE YOU ARE (SITUATIONAL AWARENESS) THERE MAY BE A TENDENCY TO HESITATE IN THIS SIT DON'T!