John, have you saved your Excel workbook to a different version at all? If
so, that may be your answer. I had my issue posted in the Sharepoint
TS.Admin thread and Roger replied with this post:
"Xlquery.xla was used in earlier versions of Excel for executing queries.
Office XP doesn't have or use xlquery.xla, but if the spreadsheet is saved
in Excel 5.0/95 format, the error may come up when opening it. Microsoft has
a workaround in KB277620 (link below). Basically, make sure you are saving
it in the latest format.

http://support.microsoft.com/default...b;en-us;277620

Roger"

I found that although I was using Excel 2000 to create the query, Excel had
been globally set to save down to Excel 95... once I fixed that and recreated
my Excel file the problem went away. Good luck.

Rgds
Sara