QUOTE(mbx @ Nov 15 2007, 06:58 PM)

Ctrl-I and Ctrl-U do not work under Leopard. Ctrl-B, however, does work.
Are you using Input Remapper through Virtualization (Parallels) when this is a problem?
If you are OSX or Parallels might be swallowing the key shortcuts. You can check if Ctrl-I is bound in the System Settings in OSX.