You use the [ and ] to raise and lower paintings, not Ctrl A. I don't think Ctrl A is used for anything. Use [ when you want to raise it up, and ] when you want to lower the object.
Hmmm... I'll have to check it when I get home tonight. I really hope it works, not so much because of the paintings but mostly for the lights and shelves.
Just to clarify - what country's keyboard are you using? I'm Portuguese living in Italy, so I had to buy an Italian computer and it came with an Italian keyboard, and those parenthesis do not feature there... On the other hand, and since I more often than not need to write in Portuguese, I set the computer to "think" it's getting its input from a Portuguese keyboard, in which those parenthesis are placed under keys 8 and 9 (and I need AltGr to access them).