I have the same problem after these updates. I have a huge project, and I could jump between worksheets, 3d window and 2d window without a problem. Now it takes up to 40sec. before I can work on that page. Then the 3D window is another one, as soon as you marquee something, you get dark(to black) parts and parts that is fully textures. The worst is objects from the Library turns into a solid colour no matter what material is assigned.
Help I'm going of my rocker. Graphisoft is not doing anything about it!!