I have the same exact issue. I have tried several different characters but get the same result. I am going to try reinstalling tonight to see if that helps (although there is no reason why it should). I will let you know if I find any way to fix this.
I fixed it by removing the game data including the patch (but not my save data) from the PS3's hard drive, and then reinstalling from scratch. I have no idea why that would solve anything, but it evidently did, because my world now loads fine, and I can explore wherever I want. Hopefully it will work for you as well!