Also, I checked the file size using the filesave function and it reports the correct file size.

I have tried this using MSIE 6 and Netscape 6.  I tried this from both WinXP and Win2000 workstations.  

My function looks like:

function DownloadFile($filename)
{
    // Check filename
    if (empty($filename))
    {
        return FALSE;
    }
    // Create download file name to be displayed to user
    $saveasname = basename($filename);
    header('Content-Type: application/octet-stream');
    header('Content-Length: '.filesize($filename));

    $browser = $_SERVER["HTTP_USER_AGENT"];
    if (preg_match('/MSIE 5.5/', $browser) 
        || preg_match('/MSIE 6.0/', $browser))
    {
        header('Content-Disposition: filename="'.$saveasname.'"');
    }
    else
    {
       header('Content-Disposition: attachment; filename="'.$saveasname.'"');
    }
    header('Content-Transfer-Encoding: binary');

    // Output file
    readfile($filename);
    // Done
    return TRUE;
}

Does the end of your script have a blank line after the ?>,
or do you have an auto_prepend file or some other include file that has this??

Actually, it does.  Two blank lines to be precise.  I just removed those lines and tested and it works fine.  Sorry about that.  Shows I am new to PHP, but I love it so far.

Thanks.

user error -> bogus