Hakan,

Recently I also had a problem with the newest version of SH3D. It turns out the problem was with the Java version (IceTea) I had installed on my computer.

This is how I solved it under Ubunru 12.04 with the Gnome Classic interface:
1 - uninstall IceTea Java through the software centre.
2 - using the terminal, install Java 7 using some help pages from the internet (like this one )
3 - now download and install SH3D
4 - you can now start SH3D as follows: Application --> Java Web Start --> SH3D

Works like a charm for me.

Hans