IE7 's unauthenticated publisher MSXML 5.0 security issues

A reader using IE7 told me that when I browsed the content of my blog using IE7, I was prompted with the message: "This site needs to run the following add-ins:" MSXML 5.0 in Microsoft Corporation (unauthenticated publishers). If you trust the Web site and the add-in and allow the add-in to run, click here ...

I have installed IE7, feel very unaccustomed, and then changed back to IE6, and I use IE6 and Firefox to visit my blog has never this phenomenon, why the use of IE7 will prompt this information?

After my analysis of the blog code, I think it may be because I installed a "blog voting plugin" Reason, the plug-in's JavaScript code, in order to achieve Ajax effect, the use of XMLHttpRequest objects, therefore, This may be because the local execution of the XMLHttpRequest object in IE7 is MSXML5.0 to reject execution, so after the local installation of MSXML 5.0 (version after Office 2003), "Unauthenticated MSXML 5.0" pops up in IE7.

This does not calculate IE7 or MSXML bugs, anyway this error message I currently can not reproduce on my computer, this situation, please try to install the latest version of MSXML, or modify the IE7 security settings will not have similar problems.