Chris,

In the past, before U-11.04, I've had some problems as well. When I install SH3D, I never use the Java Web Start version, but always the installed version. In my case the 64 bit version. I first delete or uninstall all Java versions. I then download and unzip SH3D in its own directory. I can then start the program by double-clicking SweetHome3D, a shell script of 771 bytes.

When you open the script with gedit, you will see that it defines or loads a lot of things. What may be of interest to you is -Xmx????m. This sets the amount of memory SH3D can use. If you have enough memory, you could set it to -Xmx2048m. This may solve the problem you encounter when creating videos.

Hans