Large-ish 3D model vanishes in 3D window HELP!

[Karl Barker]

In the 3D window, if a largish Archicad 16 model, I am having a major issue where if I have just the right sized marquee, I can make my model disappear partially with a live cut plane. If the marquee is smaller, then no problems, the model is fine, if the marquee is bigger, no model at all.

I have the latest build of Lion, latest AC16 build, a 1GIG graphics card (of note it is even worse on a 1/2 GIG graphics card.
Below are some images of what is happening.

Anyone else ahd the issue, or got any ideas to work around?
I ahve also manually turned antianalysing on, but tried on a machine without the antianalising on and got the same result.

[Karl Barker]

More views:

[David Maudlin]

Karl:

This looks like the bug described here:
Bugs/Model cut in 3D

HTH

David