This is not a bug in mustang java web start.
When you do "javaws http://www.xoetrope.com/zone/articles/files/carouselcomponents/webstart/CarouselComponents_ip.php", we will go download the url and read in as the jnlp contents.
If there is an href in the jnlp file, (in this case, http://www.xoetrope.com/zone/articles/files/carouselcomponents/webstart/CarouselComponents_ip.jnlp), we will then contact the href again, and use that as the jnlp file.
however, http://www.xoetrope.com/zone/articles/files/carouselcomponents/webstart/CarouselComponents_ip.jnlp is a invalid url and returns 404, so java web start will not launch the application, because it cannot download the jnlp file.
the href in the jnlp file must be valid; or the href should not be specified.
in tiger it works because we store the contents of http://www.xoetrope.com/zone/articles/files/carouselcomponents/webstart/CarouselComponents_ip.php as a cache entry for http://www.xoetrope.com/zone/articles/files/carouselcomponents/webstart/CarouselComponents_ip.jnlp, which is not correct.
I will try to contact xoetrope.com and ask them to fix the jnlp file.