NPE in Sitemap Source

[Vadim Gritsenko]

There is a problem with internal requests error handling; for some  
reason it causes NPE in the cocoon: source. Check this out:

http://cocoon.zones.apache.org/demos/trunk/samples/core/errorhandling/internal/aggregate/custom-sitemap
http://cocoon.zones.apache.org/demos/trunk/samples/core/errorhandling/internal/include/custom-sitemap
Currently it results in NPE in the SitemapSource.java:293, but it  
should generate output similar to these pages:

http://cocoon.zones.apache.org/demos/trunk/samples/core/errorhandling/internal/aggregate/custom-setup
http://cocoon.zones.apache.org/demos/trunk/samples/core/errorhandling/internal/include/custom-setup

Any clues why this is happening?

Vadim