What platform are you developing on? You might try a couple of things:
1) Bring your code over to the ccc.wpi.edu systems and see if it behaves the same. This can help you tell if it is your platform (terminal and/or curses setup).
2) Try explicitly turning off the cursor in the graphics manager. Put a curs_set(0) call in the startup. Normally, this is in the InputManager but see if it helps here.