Mischa,

To correctly install SH3D v3.4 on your Ubuntu 11.10 machine, proceed as follows:
- uninstall all versions of Java on your PC
- download the 64 bits version of SH3D
- unzip the file in the directory where you want the program to be (no need to use apt-get or something similar)
- go to the directory where you unpacked SH3D and double-click the file SweetHome3D (818 bytes) to launch the program

That's all. It works fine on my Ubuntu 11.10 64-bits PC.

Hans