AN MD83 ON FLARE AT 50 FT AGL HAD THE STALL WARNING AURAL; STICK SHAKER; AND STICK PUSHER ALL ACTIVATE SIMULTANEOUSLY.

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WE WERE FLYING ACR FLT XYZ FROM SEATTLE TO LOS ANGELES ON NOV/SAT/98. WE WERE CLRED FOR A VISUAL APCH TO RWY 24R AT LAX. IN THE LNDG FLARE; TRIMMED AT VREF AT APPROX 50 FT AGL; THE AURAL STALL WARNING; STICK SHAKER AND STICK PUSHER ALL ACTIVATED. AUTOTHROTTLES ON; AUTOPLT OFF. WE WERE ON A STABILIZED VISUAL APCH; 5+ MI SEPARATED BTWN US AND THE ACFT AHEAD OF US. THE ACFT THAT WE WERE FOLLOWING WAS A NON-HVY TURBOJET (EXACT TYPE UNKNOWN). WINDS WERE LIGHT AND NO RPTED WINDSHEAR IN THE AREA. THE ACFT WEIGHED 122000 LBS. WE HAD THE SPD BUGS SET USING THE V SPD REF CARD DATA FOR OUR FLAPS 40 DEGS LNDG WHICH RESULTS IN A VREF SPD OF 128 KTS. IT IS OUR AIRLINE'S STANDARD PROC TO SET THE AUTOTHROTTLE SPD REF WINDOW TO VREF +5 KTS. THE RESULTANT SPD SET IN THE AUTOTHROTTLE SPD SELECT WINDOW WAS 133 KTS. I (THE FO) WAS THE PF AND THE CAPT WAS DOING THE STANDARD PNF'S DUTIES WHICH AT THE TIME OF THE INCIDENT INCLUDED CALLING OUT AIRSPDS AND SINK RATES. SINCE THERE WAS NO WINDSHEAR RPTED; NO WAKE TURB; NO WIND GUSTS; AND NO ABNORMAL INDICATIONS OF ANY SORT IT WAS QUITE AN UNEXPECTED AND VERY SURPRISING EXPERIENCE. THE PITCH ATTITUDE WAS NORMAL; THE INDICATED AIRSPD WAS NORMAL; THE PWR SETTING WAS NORMAL AND THE AUTOTHROTTLES WERE ON. SINCE WE ARE TRAINED TO ALWAYS RESPECT STICK SHAKER IN WINDSHEAR RECOVERY AND STALL RECOVERY TRAINING; IN THE SIMULATOR; I WAS VERY RELUCTANT TO INCREASE MY PITCH ATTITUDE AS I WOULD NORMALLY DO APCHING THE LNDG FLARE PHASE OF FLT. HOWEVER; BECAUSE OF OUR VERY CLOSE PROX TO THE GND (APPROX 50 FT AGL) I WAS NOT IN A POS TO TRADE ANY PITCH ATTITUDE FOR DECREASED ANGLE OF ATTACK AS I FELT THAT THIS WOULD RESULT IN POSSIBLE AIRFRAME DAMAGE DUE TO EXCESSIVE SINK RATE. MY ONLY OTHER OPTION WAS TO ADD PWR; LOTS OF IT; ALL THE WAY TO THE MECHANICAL STOPS; WHICH I DID. WE CONTACTED THE RWY IN A FIRM LNDG AND WROTE UP THE STALL WARNING SYS IN THE MAINT LOG. I PERFORMED A THOROUGH POSTFLT INSPECTION OF THE ACFT ALONG WITH A MECH. NOTHING ABNORMAL OBSERVED. MAINT REPLACED ONE OF THE STALL WARNING COMPUTERS AND ONE OF THE AOA VANES AND INHIBITED THE STICK PUSHER SYS AND RELEASED THE ACFT TO SVC USING APPROPRIATE MEL PROCS. WHAT CAUSED THIS? I'M NOT SURE; PERHAPS THE NEXT CREW'S EXPERIENCE WILL SHED SOME LIGHT ON THE SUBJECT. THE NEXT CREW; WHILE ON APCH TO THE PUERTO VALLARTA ARPT OBSERVED A SLAT DISAGREE LIGHT WHILE ON APCH TO THE ARPT. THE SLAT DISAGREE LIGHT ILLUMINATED EARLY ENOUGH IN THE APCH TO ALLOW THE CREW TIME TO FOLLOW THE QRH PROCS FOR THE SLAT DISAGREE LIGHT ILLUMINATED PROC. THEY WERE ABLE TO LAND WITHOUT FURTHER INCIDENT AND HAVE MAINT PERFORMED ON THE ACFT. IN OUR CASE; ALTHOUGH WE NEVER OBSERVED THE SLAT DISAGREE LIGHT; IF THE SLAT DISAGREE SYS SENSED THE SLATS WERE PERHAPS RETRACTED; THIS MIGHT ACCOUNT FOR THE STALL INDICATION. VREF SPD FOR FLAPS 40 DEGS WITH SLATS RETRACTED IS CONSIDERABLY FASTER THAN NORMAL FLAPS 40 DEG SLATS FULLY EXTENDED. THIS IS ONLY A HYPOTHETICAL EXPLANATION HOWEVER; AS WE NEVER OBSERVED THE SLAT DISAGREE LIGHT ILLUMINATED EITHER INFLT OR AFTER LNDG.