I will check the faq...
Also I tried the project on three different computers. 2 Win7 64bit and one 64bit kubuntu. Always the same problem, I think the project is simply too big and needs more Ram than java is possible to use.

Here the link:
http://www.megaupload.com/?d=HL7KOPUY

Dach-Fläche13-aussen.sh3d
Dach-Fläche13-innen.sh3d
Dach-Gaube17-aussen.sh3d
Dach-Gaube17-innen.sh3d

these 4 files are parts of the roof


Dach-Komplett.sh3d

are the connected 4 roof-parts


Wohnung72.sh3d

is the main apartment-part


Wohnung72-Dach.sh3d

is the connected Wohnung72.sh3d with the Dach-Komplett.sh3d


'Till here it's teribble slow, but it works.
Now I need to export Wohnung72-Dach.sh3d to the Stiege1.sh3d which is the ground-level and this is not possible to do.