As promised here a link to my first "blog" http://www.pbjar.org/blogs/jxlayer/JXLayer_one.html Just wrote it in plain simple html what I am not very good at. To have the sample work via webstart I had to sign my jar but also your jar. So I took the liberty of signing it under my name. I hope you don't mind. As soon as you sign your jar yourself I will change the jnlp file and redirect it to another jnlp file for your jar.
This is the link:
If there is anything that you don't like, please let me know and I'll change it.