The problems are different at each site. www.schnigge.de has a large number of pages that are not URL driven. Many of of its links are generated by client side javascript . The crawler will not follow links that require it to execute client side javascript.
Also, www.schnigge.de has an off-site <IFRAME>; since it is the only <IFRAME> that page fails. You could fetch just that page with -o and -g, then continue the walk without -o and -g to get the rest of the site.