How to get to info mode

[eric5931]

I'm using emacs 23.1.1 in a new RHEL 5 host. When I visit any INFO
files, like /usr/share/info/dir, somehow the emacs didn't get to INFO
mode as in my other hosts. Instead, it is in  "Text Fly" mode and I
cannot use the links to see related info. How could I set it to info
mode?

Also, do I need to do anything in my .eamcs to let it automatically
goto info mode? I thought emacs should do this by itself.

Eric