I am experiencing the same problem on two of my computers (running XP) but my third computer running Vista seems fine - so far. I first had the problem on my desktop, so I went and tried it on my notebook and it worked fine. Then a week or so later it would not work on my notebook either. My wife's computer is Vista and so far no problem there.
I e-mailed Sony Support, received a reply with a link giving directions to disable security software and try it. That made no difference. Last resort I guess will be to endure the frustration of spending some time on the phone.