Again I find myself running into problems with IE, today its with it's DOM support.
I recently wrote some JavaScript to look at a links href attribute to detect if the link was external or not (the existence of HTTP:// would show it was external). The problem was that Internet Explorer showed the absolute href rather than the text content of the attribute in the DOM. Therefore it meant that every link had HTTP:// in it's href attribute.
I discovered that you could pass a section option in the JavaScript for .getAttribute that would force IE to return the value of the href in the DOM rather than how it saw it. This was found via Glenn Jone's post on Internet Explorers getAttribute href bug.
Another day another IE work around... sigh