The official and most independent Component cables have a simple 'TV' switch on the console plug end. That will put it into standard definition (SD) mode which, hopefully, should allow you to re-set the console to 60Hz.
But why the update should have caused a PAL console to switch to 50Hz is odd.
I can testify to the switch on the cable that'll fix it. I had this problem too when I loaded up BM a while ago, and had to figure out what to do to fix it. I don't know any other game to do this, it's a little frustrating, but it's possible to get around.