Can't Output To Excel 2000

I can't seem to get Excel 2000 to translate an html page. I have Excel 97 perform the same task without a problem, but 2000 just diplays a series of broken image icons.
This the code that I am using to connect to Excel-

Header("Content-Disposition: inline; filename=myfile.xls");
Header("Content-Description: PHP4 Generated Data");
Header("Content-type: application/vnd.ms-excel; name='MIMS_Excel'");
flush;

Is it a coding issue or a setting on Excel that I don't know about, or is it simply impossible.