Users navigating the site with IE (Microsoft's Internet Explorer) will double count the downloads if the site not in the users's trusted zone. When you visit a site which uses the automatic download prompt, the Information bar appears instead of the download window. This is due to a security enhancement to protect the users from rogue websites. To download the file you need to click the Information bar and select Download file option to download the file. This is all well and good but it results in a double download count and will restrict the number of files you can download in a 24 hour period.
To get the most from the site you need to add www.ExcelCalcs.com to your trusted zone to avoid the problem altogether.
There is also a problem with the automatic startup of downloads in IE7. This is because of a block put on automatic JavaScript running when a window loads. You can remove the block by enabling the security option "Allow websites to prompt for information using scripted windows" which is near the end of the list in Tools - Internet Options - Security.