WDB APPARENTLY ISSUED WRONG CLRNC AND DESCENDED TO OTHER THAN COORD ALT OVER DBQ; SECOND CTLR CORRECTED ALT ASSIGNMENT.

Narrative

EBND J-84 AT FL370 ABOUT 80 NM W OF DBQ VOR FOR ORD LANDING. CENTER CLRED US TO; 'DSND TO AND CROSS DBQ AT FL230.' I READ BACK THE CLRNC AND SET 230 IN THE ALT ALERT. THE F/O STATED TO ME; PER COMPANY SOP'S; 'CLRED TO CROSS DBQ AT FL230.' ABOUT 4 MIN LATER I RPTED LEAVING FL370 TO CROSS DBQ AT FL230. CENTER ACKNOWLEDGED BOTH OF MY RADIO CALLS AND APPEARED TO BE CONTENT AND HAPPY WITH OUR PROGRESS. JUST AS WE WERE LEVELING OFF AT FL230 3 TO 4 MI W OF DBQ; CENTER SAID IN A VERY CONCERNED SOUNDING VOICE; 'CLB NOW TO FL240.' WE DID THIS WITH HASTE; AND I ASKED WHY. HE SAID WE HAD BEEN CLRED (FROM FL370) TO CROSS DBQ AT FL330 AND DSND TO FL240. UP UNTIL WE WERE TOLD TO CLB NOW TO FL240; IT HAD NOT EVEN BEEN MENTIONED TO US! WE HAD NOT RECEIVED THE CLRNC THAT THE SECTOR CTLR FOR THE DBQ VOR THOUGHT WE HAD RECEIVED. WE HAD CHANGED FREQS AND CTLRS AT SOME POINT BTWN THE ORIGINAL CLRNC TO CROSS DBQ AT FL230 AND OUR ARR AT FL230; I THINK CENTER GAVE US A CLRNC MEANT FOR ANOTHER ACFT. I READ BACK THE ORIGINAL CLRNC; REPEATED IT WHEN LEAVING FL370 AND IN BOTH CASES; CENTER APPEARED HAPPY WITH OUR INTENTIONS.