The reason for the pop-up is as follows:
Internet Explorer 8 displays a security warning box when you're on a secure, https-Protocol-using website that at temps to load non-secure content over the HTTP protocol. HTTPS content is encrypted so no one can snoop on your personal information, but HTTP
Is not. HTTP Content on an HTTPS website can cause sensitive information such as credit card numbers to be sent unencrypted, so IE 8 displays a security warning. if you realize the risks and don't want to see this error message every time a website loads non-secure
Content on a secure web page, you can disable the security warning.
Generally, the content transmitted over HTTPS is encrypted, but HTTP is not. Therefore, if the HTTP content is sent to an HTTPS website, IE8 will display a warning message.
Follow these steps:
Instructions
1 click "Tools" and "Internet Options" in the Internet Explorer window. Open IE and select Tools> Internet Options.
2 click the "Security" tab at the top of the "Internet Options" window. Select the Security Tab
3 select a zone for which to disable the security warning, such as "Internet," by clicking its name. Select a zone to remove the warning, generally Internet
4 edit the security settings by clicking the "Custom Level" button. Open Custom Level
5 scroll down until you see "Display mixed content" under the "Miscellaneous" header in the "Settings" list. Find the "Display mixed content" option under miscellaneous.
6 click the "enable" radio button under "Display mixed content. "This is set to" prompt "by default. "enable" causes mixed content to be displayed with no security warning. select enable. The default value is prompt.
7 save your settings by clicking "OK" twice. Select OK to save
Address: http://www.ehow.com/how_6899569_disable-ie-8-security-warning.html