Can't modify objects after creation in object mode

Question

I don't know what I pressed, but this happened before.

1. I can't undo or redo in object mode but it still works in edit mode.
2. When I move an object to another layer I need to press an "OK" button.
3. Can't use the lower half of the left toolbar in object mode, it is grayed out.

Here are a couple pictures:

What is causing this strange behavior?