CSS problems with Internet Explorer

You have a </div> missing which might explain it.
https://validator.w3.org/check?uri=http%3A%2F%2Fblog.troelsmyrup.dk%2Findex.php&charset=%28detect+automatically%29&doctype=%28detect+automatically%29&ss=1&verbose=1

It seems to be fixed now. I think there’s a series of problems with the Dark Fire template. For one thing, it is missing character encoding.
Thanks for the quick response.

Assuming you are using the original index file included in the download you will find that character encoding is actually a php call to the setting in your blog admin. It might not be apparent as there is no encoding mentioned in the call.