How can I open an Excel 2003 HTML file in Excel 2007
 

I have a web site that writes it's output as file.xls. The file is really an
html file. In 2003 Excel figures it out and opens the file. In 2007 it says
it does not match and chokes. I then rename the file and it tries to load the
entire table into a single cell.

Any advise or knowledge on how to get 2007 to be as smart as 2003?

Thanks