Comment 2 for bug 969520

Tested on a laptop atm (packages are up-to-date on both machines).
A click on .jnlp file opens the dialog and suggests to open it with java webstart.
The file will be downloaded to /tmp, after notification of successful download nothing happens.

Although there is no java -6* installed .xsession-errors says something else when trying to open the file with icedtea webstart:
/usr/bin/javaws: Zeile 66: /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java: No such file or directory

Same output when running in a terminal:
~$ ICEDTEAPLUGIN_DEBUG= firefox
ACR (Component): component init
Running global cleanup code from study base classes.
/usr/bin/javaws: line 66: /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java: No such file or directory

ii icedtea-7-jre-cacao 7~u3-2.1.1~pre1-1ubuntu1
ii icedtea-7-jre-jamvm 7~u3-2.1.1~pre1-1ubuntu1
ii icedtea-7-plugin 1.2-2ubuntu1
ii icedtea-netx 1.2-2ubuntu1
ii icedtea-netx-common 1.2-2ubuntu1

ii openjdk-7-jre 7~u3-2.1.1~pre1-1ubuntu1
ii openjdk-7-jre-headless 7~u3-2.1.1~pre1-1ubuntu1
ii openjdk-7-jre-lib 7~u3-2.1.1~pre1-1ubuntu1

No alternatives, nothing to configure.
OpenJDK Runtime Environment (IcedTea7 2.1.1pre) (7~u3-2.1.1~pre1-1ubuntu1)
OpenJDK 64-Bit Server VM (build 22.0-b10, mixed mode)