WordPress RSS Feed 404 and redirect to homepage

I seem to have an annoying problem with the RSS feeds of my WordPress installation. When I try to look at them they redirect me to the homepage:

http://www.nemesys.nl/feed

When I look at the code of the homepage and click on the RSS feed I get the following XML code:

<?xml version="1.0" encoding="UTF-8"?>
    <rss version="2.0"
    	xmlns:content="http://purl.org/rss/1.0/modules/content/"
    	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
    	xmlns:dc="http://purl.org/dc/elements/1.1/"
    	xmlns:atom="http://www.w3.org/2005/Atom"
    	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
    	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
    	>

    <channel>
    	<title>NEMESYS » Page not found</title>
    	<atom:link href="https://www.nemesys.nl/feed/" rel="self" type="application/rss+xml" />
    	<link>https://www.nemesys.nl</link>
    	<description>Duidelijk in ICT</description>
    	<lastBuildDate>Fri, 19 Jul 2013 08:20:12 +0000</lastBuildDate>
    	<language>nl-NL</language>
    	<sy:updatePeriod>hourly</sy:updatePeriod>
    	<sy:updateFrequency>1</sy:updateFrequency>
    	<generator>http://wordpress.org/?v=3.5.2</generator>
    	</channel>
    </rss>

Does anyone have any idea what is causing this?
Thanks in advance.