You know, journalists don't refer to Senator Frist by "Bill" and and they sure as hell don't refer to the President as just "George". We look at the headline and have a pretty good guess of whom they are talking about, yet why didn't they ues the proper (and far more unique) last name of the California governor in the headline instead.
As I said above, this has been changed since it first appeared. One wonders, however, what other Arnolds could people have mistaken it for. Palmer? Ziffel? Or perhaps the beloved title character from Hey, Arnold! on Nickelodeon? Hell, he looks about as well informed as Schwarzenegger on the issue of Chinese trade.