EMB170 FLT CREW DOES NOT MEET XING RESTR DURING ARR TO DFW.

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WE WERE ON THE BONHAM FIVE ARR INTO DFW. ATC ISSUED US INSTRUCTIONS TO CROSS KARLA INTXN AT 11000 FT AND TO MAINTAIN 300 KTS UNTIL FURTHER ADVISED. WE ENTERED AND CONFIRMED THE XING RESTR INTO THE FMS AND ALT SELECTOR AND BEGAN OUR DSCNT. DURING THE DSCNT; ATC ADVISED US WHICH RWY TO EXPECT. I ENTERED THE NEW RWY INTO THE FMS; WHICH INVOLVES REENTERING THE ARR PROC. THIS ALSO RESETS THE XING RESTR ALT ENTERED EARLIER AND ENTERS A DEFAULT ALT; WHICH IN THIS CASE WAS HIGHER. I WAS UNAWARE OF THIS AND THEREFORE DID NOT RECHK THE MANUAL VNAV ALT. THIS RESULTED IN AN INCORRECT ARTIFICIAL GLIDEPATH INDICATION; WHICH WE FOLLOWED. WE REALIZED OUR MISTAKE 10 MI FROM KARLA INTXN; STILL 6000 FT HIGH. ATC QUERIED US IF WE WOULD MAKE THE XING RESTR AND WE INFORMED THEM THAT IT WOULD BE CLOSE. ATC THEN SLOWED US FROM 300 KTS TO 250 KTS WHICH FURTHER REDUCED OUR DSCNT RATE. WE CROSSED KARLA 1000 FT ABOVE OUR XING RESTR. BEING AWARE OF THE FMS CONDITION; WHICH RESETS VNAV ALTS WHEN CHOOSING A NEW RWY ON THE SAME APCH; I WILL RECHK ALTS ENTERED MANUALLY. ALSO; BEING MORE SITUATIONALLY AWARE; BY CALCULATING OUR DSCNT RATE MENTALLY AS A BACK-UP TO THE AUTOMATION; SHOULD REDUCE THE POSSIBILITY OF THIS SITUATION REOCCURRING.