Why would the structured reference at the end of the following formula, {=AVERAGE(IF(((DATES>=TODAY()-$G6)*(HOUR(DATES)<12))>0,(tblBP[SYS])))}, automatically get changed to {=AVERAGE(IF(((DATES>=TODAY()-$G6)*(HOUR(DATES)<12))>0,(BP!$B$3:$B$880)))} once the workbook is saved and I exit Excel? Every time I go back into Excel and open the workbook the formula has been changed to reflect fixed cell references rather than the original structured table reference.

I have the "Use table names in formulas" option checked. I am using Excel 2007.