CTLR THOUGHT ACR X LANDED WRONG RWY.

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WHEN LNDGS ARE TO THE S AT DFW; WE ALWAYS LAND ON RWY 17L WHICH IS CLOSEST TO OUR CARGO RAMP. TODAY WE REQUEST FROM APCH CTL AN ILS TO RWY 17R FOR 'AN EQUIP CHK;' SINCE THE GS ON RWY 17L WAS OTS. WE WERE CLRED FOR THE ILS RWY 17R APCH. AFTER SWITCHING TO TWR; WE WERE CLRED TO LAND. BOTH THE FO AND SO HEARD 'CLR TO LAND ON RWY 17R.' I DID NOT HEAR THE RWY DESIGNATION; BUT HEARD THE FO READ BACK 'CLRED TO LAND IN RWY 17R.' WE FINISHED ACFT CONFIGN AND THE 'BEFORE LNDG CHKLIST.' FOR MY OWN PIECE OF MIND; I THEN ASKED THE CREW IF WE WERE CLRED TO LAND ON RWY 17R; BOTH FO AND SO CONFIRMED THAT. AS WE WERE CLRING RWY 17R; TWR ASKED SOMETHING LIKE; 'DIDN'T I CLR YOU TO LAND ON RWY 17L?' THE FO RESPONDED 'WE WERE CLRED RWY 17R ALL THE WAY.' THERE WAS NO FURTHER RELATED CONVERSATION BTWN US AND TWR. I DON'T KNOW WHERE THE MIX-UP WAS; BUT TWR OBVIOUSLY THOUGHT HE HAD CLRED US TO LAND ON RWY 17L. IF HE DID; HE DIDN'T HEAR US READ BACK RWY 17R. AS A SIDE NOTE: A COMMERCIAL AIRLINER WAS CLRED BY GND CTL TO CROSS RWY 17R; FROM L TO R; AT MID-FIELD; WHILE WE WERE ON A 2-3 MI FINAL. HE WAS CLR OF RWY 17R WHEN WE WERE AT ABOUT 150 FT AGL. PRIOR TO LNDG THIS COULD HAVE BEEN AN INDICATION THAT TWR DIDN'T REALIZE WE WERE APCHING RWY 17R; BUT AT DFW 'EXPEDITING' ACROSS RWYS IS COMMON. SUPPLEMENTAL INFO FROM ACN 307651: FINAL CTLR VECTORED US FOR AN ILS TO RWY 17R AND CLRED US FOR AN APCH TO RWY 17R BEFORE SWITCHING US TO TWR. AT THIS TIME WE WERE BUSY HOOKING UP THE AUTOPLT AND RUNNING A LNDG CHKLIST. WE WERE ABOUT 2 MI INSIDE THE MARKER BEFORE ESTABLISHING COM WITH TWR. AS PNF I INFORMED TWR THAT WE WERE JUST INSIDE THE MARKER FOR RWY 17R AND WE WERE CLRED TO LAND BY TWR. I READ BACK 'CLRED TO LAND RWY 17R' NOT ONCE BUT TWICE TO INSURE EVERYONE KNEW WHAT WE WERE DOING. AFTER LNDG TWR INFORMED US THAT WE HAD BEEN CLRED TO LAND RWY 17L. AT NO TIME WERE WE TOLD TO CHANGE TO RWY 17L NOR WERE WE ASKED TO SIDESTEP.