I also recently discovered this 60Hz ghosting problem, took me a while to work out what it was and that it just occured on 60Hz too.
It's now fixed. Onsite. Through a menu option. A secret engineer's menu. And I know how.
First, I called up for warranty repair. The guy from Mastercare showed up, admitted straight away he didn't really know much about this set. Fair enough, I didn't expect him to, there are so many sets out there you can't know everything about them all, and he was a nice guy anyway. So, I explain the problem, and he phones head office. The supervisor guy on the end of the phone is an idiot. He runs through umpteen excuses to try to fob me off, unlucky for him I'm pretty technical, and know my stuff, and I shoot him down in flames on every try.
First, he suggests that it's "normal". Then that it doesn't support 60Hz. Then he suggested that because it's 60Hz, my xbox360 is not a UK one, it's an import. Then he suggests it must be "chipped or modified". All untrue. Eventually we get past him, and my engineer dude phones up Sony. After some trouble trying to establish details and model numbers, the guy at Sony tell my engineer how to sort it. Apparently, this is not an unknown problem, Sony are aware. They know. They've worked out a solution. This guy at Sony *knew* straight away what to do. He was strong in the ways of the Clue.
Now whether the *problem* is fixed, I cannot say, but the symptoms ( the ghosting ) are gone, so I'm happy. I would like to know the real cause of this problem though, as I wouldn't like to think the solution I've been given is just covering up for something which will get worse and arise again.
If I give up this solution, which Sony almost certainly don't want you the end user to have ( this is an Engineer only menu ), on your heads be it. Use it at your own risk. You go messing with stuff in there you don't understand, you're gonna knacker your telly. Be warned. I accept no responsibility for your actions.
And the solution? erm, I have it written down, at home, and I'm at work, so you'll have to wait a few hours, sorry