Yea I noticed that you most of the time if an item is ontop of a bookcase or wardrobe looking thing when you press TAB it does not show up in the vicinity section...however if you move you mose over it slowly and use the "Dot" style crosshair it will pop up and tell you what it is then you can click the mouse wheel to pick it up that way.

I cant get screen shots either. When I hit "print screen" and try to paste the image it just shows up as a black pic. Guess the Steam Screen cap will work fine tho...have to try when I get home.