Unfortunately, I only have an unhelpful answer. I have also tried mapping the control key but, so far, have had no success. Similarly, I can't seem to get the shift lock key to work correctly.
The rest of the common keys (including home, backspace, menu and back) all map without issue.
However, this may be an issue with the keyboard I'm using. Have you tried mapping the keys to the "CTRL_LEFT" or "CTRL_RIGHT" android constants in your keylayout?