When clicking on a javaws link which is returning a jnlp file to the client, the
firefox browser correctly asks what application should be used to view the file
with IcedTea Web Start being the default.

The file is then downloaded as kvm.cgi to /tmp and passed to the javaws binary
without the javaws binary executing the downloaded file.

Calling javaws manually seems to indicate that javaws will only execute files
with the file extension .jnlp which is a bit problematic in my case as the file
is named kvm.cgi.

[athienem@localhost ~]$ javaws /tmp/kvm.cgi 

Usage:   javaws [-run-options] <jnlp file>
         javaws [-control-options]

control-options:
  -about                Shows a sample application.
  -viewer               Shows the trusted certificate viewer.

run-options:
  -basedir dir          Directory where the cache is kept.
  -arg arg              Adds an application argument before launching.
  -param name=value     Adds an applet parameter before launching.
  -property name=value  Sets a system property before launching.
  -update seconds       Update check if seconds since last checked.
  -license              Display the GPL license and exit.
  -verbose              Enable verbose output.
  -nosecurity           Disables the secure runtime environment.
  -noupdate             Disables checking for updates.
  -headless             Disables download window, other UIs.
  -strict               Enables strict checking of JNLP file format.
  -help                 Print this message and exit.

[athienem@localhost ~]$

Renaming the file to kvm.jnlp works around the problem:

[athienem@localhost ~]$ mv /tmp/kvm.cgi /tmp/kvm.jnlp 
[athienem@localhost ~]$ javaws /tmp/kvm.jnlp
[web start app updates and starts]

This problem seems not to exist with the java 1.5 package from sun as delivered
on the RHEL5 CSB app.