Adding a hosts file to the windows machine did the trick: redirects sent to the browser now work. Thanks to Nathan and Joerg.
What confused matters a little was the fact that I could access pages using the url "conrad/page_name" even before I added a hosts file, but "conrad.localdomain/page_name" (the url that would be sent in a redirect) didn't work. It turned out that "conrad" was being linked to the IP address by SAMBA, because I chose "conrad" as a server name for SAMBA. Doh!
