GPWS ALARM SOUNDS DURING APCH.

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ACFT B737-300/500 FLT YY SFO-SAN; KK45 PM. WX 15 OVCST 7 MI; TOPS APPROX 50 OVCST. ON APCH TO SAN (LOC 27) WE WERE GIVEN A R TURN TO 240 DEGS; DSND AND MAINTAIN 3800 FT; INTERCEPT THE LOC AT OR ABOVE 3800 FT; CLRED FOR THE APCH. ACFT SPD WAS 170 KTS; FLAPS 5 DEGS DSNDING AT 500 FPM; AUTOPLT ON ALT APPROX 5000 FT. WHEN PASSING THROUGH 4000 FT IN THE CLOUDS; THE GPWS CALLED 'TERRAIN; TERRAIN.' EXCEPT MANEUVER EXECUTED AND WARNING SILENCED AT ABOUT 5000 FT. NOTIFIED ATC; INTERCEPTED FINAL AND LANDED. ALL CLRNCS WERE COMPLIED WITH AND NO PROCEDURAL DEVS WERE NOTED. INCREDIBLY THE ATC CTLR SAID A PREVIOUS FLT RPTED THE SAME EXACT SIT. AS WE SPOKE; THE 2 ACFT AHEAD OF US ON FINAL XMITTED THAT THEY TOO HAD A GPWS WARNING ON APCH. TERRAIN WAS BRIEFED; AND THE LOCATION OF THE HIGHEST OBSTACLE (2791 FT) JUST N OF VYDA WOULD COINCIDE WITH ACTUAL TERRAIN CLRNC OF APPROX 1000 FT. CTLR SAID MVA FOR THIS SECTOR IS 3800 FT MSL. NOBODY LIKES A GPWS WARNING; ESPECIALLY WHEN YOU ARE OPERATING ON A NORMAL ATC CLRNC WITH NO DEV FROM SOP'S. PERHAPS THIS ALT IS TOO LOW FOR THIS TYPE OF APCH SEGMENT.