AN ACR FLC HAS A GPWS TERRAIN WARNING WHILE DSNDING ON THE JAWWS 1 ARR. THE FLC PROPERLY EXECUTED AN EVASIVE CLB TO AVOID TERRAIN. THE MVA FOR THE AREA WAS 4500 FT.

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JAWWS 1 ARR TO SJC; ESTABLISHED ON THE OAK 138 DEG RADIAL AT APPROX 30-40 DME; FO FLYING; WX SOLID IMC; ACFT ON AUTOPLT; SPD 250 KTS; VERT SPD 700 FPM DOWN; CLRED TO 4500 FT; SJC ALTIMETER 30.13; TIME APPROX XA40. WHILE DSNDING THROUGH APPROX 4800-4700 FT; WE RECEIVED A GPWS 'TERRAIN' WARNING. FO EXECUTED ESCAPE MANEUVER BY SMOOTHLY AND RAPIDLY ADVANCING THROTTLES TO THE MECHANICAL STOPS AND ROTATING ACFT PITCH TO 15 DEGS NOSE UP. WARNING CONTINUED WHILE CLBING AT 300-500 FPM. AFTER WARNING STOPPED; ACFT WAS LEVELED AT 7000 FT AND BAY APCH WAS ADVISED. WE WERE INFORMED THAT 4500 FT WAS THE MVA FOR THAT SECTOR. NO OTHER ACFT WERE OBSERVED ON TCASII IN OUR AREA. BAY APCH CLRED US TO 4000 FT AND WE PROCEEDED WITH RADAR VECTORS TO THE VISUAL APCH RWY 12R. BECAUSE OF IMC CONDITIONS; I COULD NOT CONFIRM IF WARNING WAS FALSE; SO I ASSUMED IT WAS REAL. ACFT WAS WRITTEN UP BECAUSE I CANNOT CONFIRM OR DENY THAT THE ENGS WERE NOT OVERTEMPED OR OVERSPED. CALLBACK CONVERSATION WITH BAY TRACON REVEALED THE FOLLOWING INFO: CALLED BAY TRACON AND SPOKE TO A SPECIALIST REGARDING THE GPWS PROB AT SJC. SPECIALIST SAID THEY WERE AWARE OF THE PROB AND ALSO HAD CORRESPONDENCE WITH ALPA AND THE FAA REGIONAL OFFICE. AS OF THIS TIME THEY DO NOT HAVE A SOLUTION; BUT IT MAY BE A SOFTWARE PROB WITH THE AIRBORNE EQUIP (OVER SENSITIVE TO CHANGING TERRAIN). OTHER FACILITIES; SUCH AS PDX AND DEN; ARE ALSO RPTING THE SAME. THE SPECIALIST CLAIMS THAT NO PROCEDURAL CHANGES HAVE BEEN MADE AT BAY.