Okay, my blank worksheet problem is fixed.
I changed this:
' Response.AddHeader("Content-Disposition", "inline;filename=Filename.xls")
which I think got rid of the problem where it thought it wanted to open my aspx file (if I'm remembering correctly)
Response.AddHeader("Content-Disposition", "attachment; filename=ExcelFile.xls")
but I am still having a problem where it thinks it's an invalid extension. Is there a different ContentType string I need for Excel 2007?
Thanks, this is coming together very quickly thanks to you guys.