Well, while IE is incredibly slow when it comes to handling JavaScript, the site does seem to work for me. If I wait long enough I get to see the map, can choose countries and add tiles manually. So everything is there, but somehow -in IE- an extra slash is added after ‘http://’ in the links, but it’s ok if you manually remove that.

Anyway. These are the tiles you’re looking for I guess:
http://planetosm.oxilion.nl/~lambertus/garmin/routable/12-02-2011/63240504.img
http://planetosm.oxilion.nl/~lambertus/garmin/routable/12-02-2011/63240632.img
http://planetosm.oxilion.nl/~lambertus/garmin/routable/12-02-2011/63240696.img
http://planetosm.oxilion.nl/~lambertus/garmin/routable/12-02-2011/63240792.img
http://planetosm.oxilion.nl/~lambertus/garmin/routable/12-02-2011/63240840.img