Is this really, really true, even at the very end when you can go everywhere? I didn't need to go back there, so I hadn't tried, but I know I was furious in FFIX when half of the towns became 'locked' after a certain point, really without warning. I thought FFX was great for not doing that to you, so if you put off a quest until later you weren't doomed. I'm pretty unhappy if this is the case, for those poor people that didn't finish Bevelle up "at that time".