Shift-space toggles between objects and terrain, which certainly has its uses. That said, sometimes I want to make a level title in all caps for stylistic reasons - and I usually end up holding shift to do that rather than pressing caps lock. This causes the shift-space function to trigger and prevents me from finishing typing the level title.
If a textbox has focus, and shift-space is pressed, the textbox should keep its focus. (As far as whether terrain/objects get toggled, I don't really care, as long as I can keep typing text in the box).
