Is it normal that I linked my Amazon Devlopper account by clicking on "Publish", but it always ask me to give the permission? I can't publish it with this.

hmmm you should only have to give permission once.. i remember when i first linked my account it felt like it wasn't accepting it right away.. check with the VA folks to see if they might see something going on.  

Okay problem's solved, just closed the website and tried again, it seems it was just a bug.

yea that sounds about like what i went through.. heh.  it was like the website just didn't know it was confirmed and a fresh connection sees the change.