The tracking code displayed by piwik can cause IE7 to fail to load the page.
The reason is that IE7 does not like <script> tags that are not directly under the body to append an element to body. IE7 will not display the page at all but instead show an alert box with a message. Removing the <a> around the piwik tag will solve the problem.
Not all versions of IE7 are affected - however I have reports of this from both Win XP and Vista 32 & 64bit; It seems to be spreading as I got reports about problems with other scripts (not piwik) from sites that have . There is a microsoft knowledge base article detailing the problem and offering possible fixes (there is also a browser path) - I don't have the URL right now - I will add it later to this report.
I belive this bug is similar to the one described in #229 - the duplicate referenced did have nothing to do with the cause of the problem.
Are your pages XHTML?
Is there a difference when you load the script directly, e.g.,
Can you provide a URL to one of the pages you're tracking?
Pleae also provide a URL to the Microsoft KB article that you're referring to.
The closest thing I could find was http://support.microsoft.com/kb/933873
This will be fixed by ticket 355 ... piwik.js will no longer modify the DOM by either DOM manipulation like appendChild() or document.write().