I stumbled upon an HTML5 Internet Explorer shiv issue today. It seems that the WordPress TwentyEleven theme was not including the html5 shiv script properly at some point in the past. I discovered this when a forked TwentyEleven theme started throwing weird “shiv”-related text at the top of my pages.

To solve the problem, I simply copy-and-pasted the following script into my header, while removing the old code: