Display Problem- some assets not showing up in Scene mode

I have installed Unity Pro 3.4.1. I am having a strange problem where some of the assets are not visible in my Scene view, yet show up in the Game view. I have tried creating new assets and they do not show up visibly either. The most interesting thing is that if I switch back and forth between Scene and Game view, I sometimes get a wireframe to show up on a newly created object- even if I am set to "Textured" mode. I updated my video drivers yesterday to see if that was the issue.

The Angrybots project, for example, displays what seems to be some random props, some of the collision and no floors. If I go into game mode, everything is there. Is there some option I might have inadvertently activated?

Appreciate any help.