>I have some report generation code that has worked under VFP7 for years, but now gives me an "error building key for index [cdx filename] tag [tagname] under VFP9.
>
>the code pointed to in the debugger:
>index on iif(eof('PERSONEL'),EMPNO,PERSONEL.SNAME+PERSONEL.FNAME)+dtos(date)+DUTYTIME+EXCCODE tag REPORT
>
>If I suspend the program and then immediately resume, the error disappears. I assumed that it may have been an issue with data in memory not yet written to disk, so I added a flush command - no luck, neither did a wait statement.
>
>If I run the same process in VFP7 there is no error or issue.
>
>I'm using XP SP3, 2Gb RAM and a 2.7Ghz CPU.
>
>Any suggestions would be very welcome....

VFP9 has a new SET TABLEVALIDATE setting. By default it's non-zero, and does some table checking that earlier versions do not. To see if this is the cause, you could issue SET TABLEVALIDATE TO 0 (zero) before running the suspect code.

As a side issue, you're using a couple of reserved words in your INDEX statement:

DTOS( date ) - implies you have a column named "date", not a good idea
TAG REPORT - "REPORT" is a reserved word, it's not a good idea to name an index tag after that