I have a webpage with lots of accented characters from different languages. In IE8, sometimes the page loads fine but sometimes selected accented characters (i.e. , , , ) come up as boxes. It seems completely random whether it works or not - just reloading the page without making any changes can show different results.

In my HTML header, I use
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
At the start of the PHP code, I use
PHP Code:
header('Content-type: text/html; charset=utf-8'); 
Any tips on why it's intermittently working like this?