MLG TAXIES ACROSS RWY WHEN INSTRUCTED TO HOLD SHORT.

Narrative

TAXIED ACROSS RWY 22L AT TXWY P WITHOUT CLRNC. THE FO MADE THE LNDG ON RWY 31C. WE EXITED THE RWY AT THE END AND CONTACTED GND CTL ON 121.7. GND CLRED US TO TAXI VIA TXWYS N AND P; HOLD SHORT OF RWY 22L. AS WE EXITED THE RWY; I (THE CAPT) WAS DISTRACTED BY A MALFUNCTION IN THE AUTO-SPOILER SYS. THE MOTOR THAT EXTENDS/RETRACTS THE SPOILERS WAS CONTINUING TO RUN AFTER THE SPOILERS WERE RETRACTED. I WAS ATTEMPTING TO FIX THAT PROB AS GND READ US THE CLRNC AND MISSED THE 'HOLD SHORT' INSTRUCTION. AS WE TURNED ONTO TXWY P; THE FO WAS TALKING TO COMPANY ON OUR FREQ TO GET A GATE ASSIGNMENT AND TO ALERT MAINT TO OUR PROB. HE CAME BACK ON GND FREQ JUST AS I WAS ENTERING THE ACTIVE RWY 22L. AT THAT POINT GND ADVISED WE WERE TO HOLD SHORT; BUT BY THEN I WAS ALREADY 1/2 WAY ACROSS AND COULD NOT STOP. I TOLD GND I THOUGHT I WAS CLRED TO THE GATE; BUT THE FO CONFIRMED WE HAD BEEN TOLD TO HOLD SHORT OF RWY 22L. ANOTHER B737 WAS ENTERING THE RWY WITH CLRNC TO TKOF; BUT HE SAW US AND DID NOT START THE TKOF ROLL. THIS INCIDENT WAS UNDOUBTEDLY CAUSED BY ONE CREW MEMBER BEING DISTRACTED AT ONE CRITICAL MOMENT (WHEN THE CLRNC WAS ISSUED) AND THE OTHER BEING DISTRACTED AT ANOTHER CRITICAL MOMENT (AS THE RWY WAS BEING CROSSED).