Much better after I disable tooltip mode! Now that the tool tip is displayed in the minibuffer, it still delays a bit (not that long as before, presumably for users to see the tool tip), How do I even disable that? 

Best,
Yuan

On Fri, May 18, 2012 at 1:22 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> Date: Fri, 18 May 2012 13:03:48 -0400
> From: Yuan Luo <yuan.hypnos.luo@gmail.com>
>
> Is there a way I can disable prompt regarding mouse, such as "mouse-2: copy
> to input; mouse-3: menu". Under Emacs 23.3, those prompts emerge as
> one-line GUI pop-ups which slows down the response time of my remotely
> invoked Emacs (through X). Thank you for your help!

Does "M-x tooltip-mode RET" do what you want?