I'm quite new to java too but here are some things you could try:
Check the Java alternatives config:
In a terminal type:
sudo update-alternatives --config java
Icedtea is the open source implementation of javaws so I'd choose the java-6-openjdk-i386 option.
Check you have the correct plugin installed
Make sure that icedtea6-plugin is installed
(Not sure if it's strictly needed but it might be)
Check you have icedtea-netx installed
I looked in the Software-Center at IcedTea Web Control Panel and IcedTea Java Web Start and in
More Info both show at the bottom:
version: icedtea-netx-common 1.2-2ubuntu1.3 However, there is also the package icedtea-netx which is what I installed on my system and icedtea-netx-common was installed automatically as a dependency.
Using the Aptitude package manager I saw that:
icedtea6-plugin Depends on icedtea-6-plugin and that
icedtea-6-plugin depends on icedtea-netx
Make sure you are using javaws correctly.
I use javaws to run the program 'Compass and Ruler C.a.R.' and the command looks like this:
javaws -open %U -localfile -J-Djnlp.application.href=http://zirkel.sourceforge.net/JavaWebStart/zirkel-new.jnlp /home/jesse/.java/deployment/cache/6.0/31/7bca389f-718ab01a
man javaws for details about the command.
You could also try installing C.a.R. from http://car.rene-grothmann.de/doc_en/JavaWebStart.html Start C.a.R. using Java Web Start to test if javaws is working. (I'm sure there is a simpler way to test it but I don't know what it is, sorry)
P.S. I find the Software-Center rather annoying because while it's visually very nice and great for finding new programs you might like to try, if you want to know the actual package name you have to click through to the
More Info and check the version information at the bottom to discover what the actual package name is. (hint hint developers :-)
You can check whether a package in installed on your system by opening a terminal and typing:
dpkg-query -l packagename e.g.
dpkg-query -l icedtea* or
dpkg-query -l *jdk*
You can then install the package by typing
sudo apt-get install packagename pressing tab twice will also give you a list of possible options. e.g. type
sudo apt-get install icedtea
TAB and you should get:
icedtea-6-jre-cacao icedtea-7-jre-cacao icedtea-netx-common
icedtea-6-jre-jamvm icedtea-7-jre-jamvm icedtea-plugin