java web start in Firefox 3.5.9

I needed upgrade java on my laptop because of a new version of one enterprise tool we use at work. I normally downloaded and installed Java from java.com and linked java plugin to my ~/.mozilla/plugins (in my case /usr/lib/jvm/java-6-sun-1.6.0.20/jre/plugin/i386/ns7/libjavaplugin_oji.so).

But when I restarted Firefox and browsed to a page with java web start, I got following message:

„ could not be opened, because the associated helper application does not exist. Change the association in your preferences.“

Strange was, that to simply change association of JNLP in ~/.mailcap didn’t work.

It took a while, but finally I found mozilla documentation with a hint to rename mimeTypes.rdf in Firefox profile (do not delete the default one!).

Well, when I restarted Firefox again, it gave me a same message, but when I changed it in preferences again (to /usr/lib/jvm/java-6-sun-1.6.0.20/jre/javaws/javaws) it started to work.