I don't know if anyone else has experienced this but When I first go into the game I can select my hammer and it allows me to repair existing buildings. When I decide to build something new the item comes up and I can place it, buildit, etc.

Anytime after that though, if i go back to my hammer and make it active the last thing I built pops up. Now I can change it to something else but what I want to do sometimes is turn off the object so I can go back to repairs. I can't figure out which key would let me do that. Any ideas?