Hi, I thought I'd share this one.
One of the data driven subscription reports rendering to Excel has more than 65K rows (aka theBigOne). TheBigOne doesn't fit in an old Excel 2003 XLS worksheet.
I do provide the render format for the DDS from a configuration table. I couldn't find why the correct render format wasn't used, always the XLS was used. No matter what value I provided. The obvious ones I tried where the ones visible in the interface; Excel 2003 and Excel. At no avail.
Finally I found a post referring to the rsreportserver.config where the render formats are configured. And there it was: EXCEL = Excel 2003 and EXCELOPENXML = Excel 2007 and higher for the Render Format "Get the value from the database"
cheers, Leon