I can't help agreeing with snarlz. On first reading this 'solution' seems to throw up more problems than it solves. On the other hand, as a sci-fi writer, I love the idea that you fix paradoxes by distorting probablility around the location of the paradox. If I went back in time, all my ancestors would suddenly become invulnerable from that oint forward. Whatever anybody did to kill them would be bestet by all kinds of 'accidental' failures! It's a comedy writer's dream!