HELP! what has happened to my appstore??

I have an iPhone4S 16GB unlocked
So as I traveled to China over the winter, I changed my appstore region to China.
Now that I'm back, I would want to change it back but no matter what, it would not let me.
For the past 3-4 days,
everytime I put in my U.S. address (same one as if I never changed) and submit, it just tells me Session Time Out. I forgot what the code was.
But its even worse now. Today, when i tried to change it again, this is what it looks like when I click "Featured" in appstore.



I have perfect internet connection, same thing under 4G, all other tabs in the appstore are all fine.
I have restarted the phone and see if it would help, but no, its still like this.
oh, and yes I did recently upgraded to iOS6.1

Please help!!!!!!