That's just what bothers me, why a freeze when I only want to save the rendered picture?

I have Windows 7 64 bit. Until this week I din't have this problem...

The XMX trick did the trick partially. I can now render a picture but can't save it. Th program freezes at that poit, will try deleting models tomorow.

Lately I've added a lot of new objects by grouping and texturing boxes and cylinders into custom objects. The sh3d has grown to 67.794 kB. Now I can't render pictures anymore, the rendering just freezes in the inital phase.